REFEREED JOURNAL PUBLICATIONS

2019


  1. Li. J., X. Zhu, C. Shen, X. Peng, and S. A. Cummer, Transfer matrix method for the analysis of space-time modulated media and systems, Phys. Rev. B. 100, 144311, doi:10.1103/PhysRevB.100.144311, 2019. [pdf reprint]

  2. Van der Velde, O. A., J. Montanya, J. A. Lopez, and S. A. Cummer, Gigantic jet discharges evolve stepwise through the middle atmosphere, Nature Communications, 10, 4350, doi:10.1038/s41467-19-12261-y, 2019. [pdf reprint]

  3. Chen, A B-C., H. Chen, C-W. Chuang, S. A. Cummer, G. Lu, H.-K. Fang, H.-T. Su, and R.-R. Hsu, On negative sprites and the polarity paradox, Geophysical Research Letters, doi:10.1029/2019GL083804, 2019. [pdf reprint]

  4. Shen, C., X. Zhu, J. Li, and S. A. Cummer, Nonreciprocal acoustic transmission in space-time modulated coupled resonators, Phys. Rev. B, doi:10.1103/PhysRevB.100.054302, 2019. [pdf reprint]

  5. Marisaldi, M., M. Galli, C. Labanti, N. Ostgaard, D. Sarria, S. A. Cummer, F. Lyu, A. Lindanger, R. Campana, A. Ursi, M. Tavani, F. Fuschino, A. Argan, A. Trois, C. Pittori, and F. Verrecchia, On the high-energy spectral component and fine time structure of terrestrial gamma-ray flashes, J. Geophys. Res., doi:10.1029/2019JD030554, 2019. [pdf reprint]

  6. Gerard, N. J., H. Cui, C. Shen, Y. Xie, S. A. Cummer, X. Zheng, and Y. Jing, Fabrication and experimental demonstration of a hybrid resonant acoustic gradient index metasurface at 40 kHz, Applied Physics Letters, doi: 10.1063/1.5095963, 2019. [pdf reprint]

  7. Shen, C., J. Li, Z. Jia, Y. Xie, and S. A. Cummer, Nonreciprocal acoustic transmission in cascaded resonators via spatiotemporal modulation. Physical Review B, doi:10.1103/PhysRevB.99.134306, 2019. [pdf reprint]

  8. Song, A., J. Li, C. Shen, X. Peng, X. Zhu, T. Chen, and S. A. Cummer, Broadband high-index prism, for asymmetric acoustic transmission, Appl. Phys. Lett., doi:10.1063/1.5092125, 2019. [pdf reprint]

  9. Pu, Y., S. A. Cummer, M. Briggs, B. Mailyan, M. Stanbro, and O. Roberts, Low frequency radio pulses produced by terrestrial gamma-ray flashes, Geophys. Res. Lett., doi:10.1029/2019GL082743, 2019. [pdf reprint]

  10. Fu, Y., C. Shen, Y. Cao, L. Gao, H. Chen, C. T. Chan, S. A. Cummer, and Y. Xu, Reversal of transmission and reflection based on acoustic metagratings with integer parity design, Nature Communications, doi:10.1038/s41467-019-10377-9, 2019. [pdf reprint]

  11. Andrews, J. B., P. Ballentine, C.-J. Lim, J. A. Cardenas, N. X. Williams, J. Summers, M. Strangler, D. Koester, S. A. Cummer, and A. D. Franklin, Printed electronic sensor array for mapping tire tread thickness profiles, IEEE Sensors Journal, doi:10.1109/JSEN.2019.2918061, 2019. [pdf reprint]

  12. Li, J., C. Shen, X. Zhu, Y. Xie, and S. A. Cummer, Nonreciprocal sound propagation in space-time modulated media, Phys. Rev. B, v. 99, 144311, doi:10.1103/PhysRevB.99.144311, 2019. [pdf reprint]

  13. Qin, Z., M. Chen, F. Lyu, and S. A. Cummer, A GPU-based grid traverse algorithm for accelerating lightning geolocation process, IEEE Trans. Electromagnetic Compatibility, doi:10.1109/TEMC.2019.290771, 2019. [pdf reprint]

  14. Li, J, A. Diaz-Rubio, C. Shen, Z. Jia, S. A. Tretyakov, and S. A. Cummer, Highly efficient generation of angular momentum with cylindrical bianisotropic metasurfaces, Phys. Rev. Applied, v. 11, 024016, doi:/10.1103/PhysRevApplied.11.024016, 2019. [pdf reprint]

  15. Lyu, F., S. A. Cummer, Z. Qin, and M. Chen, Lightning initiation processes imaged with very high frequency broadband interferometry, J. Geophys. Res., doi:10.1029/2018JD029817, 2019. [pdf reprint]

  16. Qin, Z., M. Chen, F. Lyu, and S. A. Cummer, A comparative study of the ray-theory model with the finite difference time domain model for lightning sferic transmission in the Earth-ionosphere waveguide, J. Geophys. Res., doi:10.1029/2018JD029440, 2019. [pdf reprint]

  17. Tian, Z., C. Shen, J. Li, E. Reit, Y. Gu, H. Fu, S. A. Cummer, and T. J. Huang, Programmable acoustic metasurfaces, Advanced Functional Materials, v. 29, 1808489, doi:10.1002/adfm.201808489, 2019. [pdf reprint]

  18. Diaz-Rubio, A., J. Li, C. Shen, S. A. Cummer, and S. A. Tretyakov, Power-flow conformal metamirrors for engineering wave reflections, Science Advances, doi:10.1126/sciadv.aau7288, 2019. [pdf reprint]

  19. Lu, G., A. Chen, S. A. Cummer, M. Briggs, Y. Wang, F. Lyu, S. Xiong, and H. Zhang, A comparative study on the sferic signals of lightning discharges associated with terrestrial gamma-ray flashes observed in North America and Asia, J. Atmos. Solar-Terrestrial Phys., doi:10.1016/j.jastp.2019.01.001, 2019. [pdf reprint]



2018


  1. Shen, C., J. Li. X. Peng, and S. A. Cummer, Synthetic exceptional points and unidirectional zero reflection in non-Hermitian acoustic systems, Phys. Rev. Materials, doi:10.1103/PhysRevMaterials.2.125203, 2018. [pdf reprint]

  2. Fu, Y., J. Li, Y. Xie, C. Shen, Y. Xu, H. Chen, and S. A. Cummer, A compact acoustic retroreflector based on a mirrored Luneburg lens, Phys. Rev. Materials, doi:10.1103/PhysRevMaterials.2.105202, 2018. [pdf reprint]

  3. Huang, A., G. Lu, J. Yue, W. Lyons, F. Lucena, F. Lyu, S. A. Cummer, W. Zhang, L. Xu, X. Xue, and S. Xu, Observations of red sprites above Hurricane Matthew, Geophys. Res. Lett., doi:10.1029/2018GL079576, 2018. [pdf reprint]

  4. Stanbro, M., M. S. Briggs, O. J. Roberts, E. S. Cramer, S. A. Cummer, and J. E. Grove, A study of consecutive terrestrial gamma-ray flashes using the Gamma-ray Burst Monitor, J. Geophys. Res., doi:10.1029/2018JA025710, 2018. [pdf reprint]

  5. Xie, Y., Y. Fu, Z. Jia, J. Li, C. Shen, Y. Xu, H. Chen, and S. A. Cummer, Acoustic imaging with metamaterial Luneburg lenses, Sci. Rep., doi:10.1038/s41598-018-34581-7, 2018. [pdf reprint]

  6. Lu, G., B. Yu, S. A. Cummer, K.-M. Peng, A. B. Chen, F. Lyu, X. Xue, F. Liu, R.-R. Hsu, and H.-T. Su, On the causative strokes of halos observed by ISUAL in the vicinity of North America, Geophys. Res. Lett., doi:10.1029/2018GL079594, 2018. [pdf reprint]

  7. Lyu, F. and S. A. Cummer, Energetic radio emissions and possible terrestrial gamma-ray flashes associated with downward propagating negative leaders, Geophys. Res. Lett., doi:10.1029/2018GL079424, 2018. [pdf reprint]

  8. McCall, M. J. Pendry, V. Galdi, et al., and S. A. Cummer, Roadmap on transformation optics, J. Opt., doi:10.1088/2040-8986/aab976, 2018. [pdf reprint]

  9. Lu, G., Y. Fan, H. Zhang, R. Jiang, M. Liu, X. Qie, S. A. Cummer, X. Qie, C. Han, and K. Liu, Measurement of continuing charge transfer in rocket-triggered lightning with low frequency magnetic sensor at close range, J. Atmos. Solar-Terrest. Phys., doi:10.1016/j.jastp.2018.02.010, 2018. [pdf reprint]

  10. Shen, C., and S. A. Cummer, Harnessing multiple internal reflection to design highly absorptive acoustic metasurfaces, Phys. Rev. Appl., v. 9, 054009, doi:10.1103/PhysRevApplied.9.054009, 2018. [pdf reprint]

  11. Bowers, G. S., D. M. Smith, N. A. Kelley, G. F. Martinez-McKinney, S. A. Cummer, J. R. Dwyer, S. Heckman, R. H. Holzworth, F. Marks, P. Reasor, J. Gamache, J. Dunion, T. Richards, and H. K. Rassoul, A terrestrial gamma-ray flash inside the eyewall of Hurricane Patricia, J. Geophys. Res., doi:10.1029/2017JD027771, 2018. [pdf reprint]

  12. Shen, C., A. Diaz-Rubio, J. Li, and S. A. Cummer, A surface impedance-based three-channel acoustic metasurface retroreflector, Appl. Phys. Lett., doi: 10.1063/1.5025481, 2018. [pdf reprint]

  13. Li, J, C. Shen, A. Diaz-Rubio, S. A. Tretyakov, and S. A. Cummer, Systematic design and experimental demonstration of bianisotropic metasurfaces for scattering-free manipulation of acoustic wavefronts, Nature Communications, doi:10.1038/s41467-018-03778-9, 2018. [pdf reprint]

  14. Shen, C., Y. Xie, J. Li, S. A. Cummer, and Y. Jing, Acoustic metacages for omnidirectional sound shielding, J. Appl. Phys., v. 123, 124501, doi:10.1063/1.5009441, 2018. [pdf reprint]

  15. Liu, F., B. Zhu, G. Lu, J. Lei, A. Chen, K.-M. Peng, A. Huang, S. A. Cummer, M. Chen, M. Ma, F. Lyu, and H. Zhou, Observations of blue discharges associated with negative narrow bipolar events in active deep convection, Geophys. Res. Lett., doi: 10.1002/2017GL076207, 2018. [pdf reprint]

  16. Lyu, F., S. A. Cummer, P. R. Krehbiel, W. Rison, M. S. Briggs, E. Cramer, O. Roberts, and M. Stanbro, Very high frequency radio emissions associated with the production of terrestrial gamma-ray flashes, Geophys. Res. Lett., doi:10.1002/2018GL077102, 2018. [pdf reprint]

  17. Jia, Z., J. Li, C. Shen, Y. Xie, and S. A. Cummer, Systematic design of broadband path-coiling acoustic metamaterials, J. Appl. Phys., doi:10.1063/1.5009488, 2018. [pdf reprint]

  18. Fu, Y., Y. Xu, H. Chen, and S. A. Cummer, Coherent perfect absorption and laser modes in a cylindrical structure of conjugate metamaterials, New J. Phys., doi:10.1088/1367-2630/aa9cbd, 2018. [pdf reprint]


2017


  1. Mezentsev, A., N. Lehtinen, N. Ostgaard, F. J. Perez-Invernon, and S. A. Cummer, Spectral characteristics of VLF sferics associated with RHESSI TGFs, J. Geophys. Res., J. Geophys. Res., doi:10.1002/2017JD027624, 2017. [pdf reprint]

  2. Singh, R., A. K. Maurya, O. Chanrion, T. Neubert, S. A. Cummer, J. Mlynarczyk, S. Kumar, M. B. Cohen, and D. Siingh, Assessment of unusual gigantic jets observed during the Monsoon season: First observations from the Indian subcontinent, Sci. Rep., v. 7, 16436, doi:10.1038/s41598-017-16696-5, 2017. [pdf reprint]

  3. Fu, Y., Y. Cao, S. A. Cummer, Y. Xu, and H. Chen, Coherent perfect absorber and laser modes in purely imaginary metamaterials, Phys. Rev. A., v. 96, 043838, doi:10.1103/PhysRevA.96.043838, 2017. [pdf reprint]

  4. Liu, N., J. R. Dwyer, and S. A. Cummer, Elves accompanying terrestrial gamma-ray flashes, J. Geophys. Res., doi:10.1002/2017JA024344, 2017. [pdf reprint]

  5. Bowers, G. S., D. M. Smith, G. F. Martinez-McKinney, M. Kamogawa, S. A. Cummer, J. R. Dwyer, D. Wang, M. Stock, and Z. Kawasaki, Gamma-ray signatures of neutrons from a terrestrial gamma-ray flash, Geophys. Res. Lett., doi:10.1002/2017GL075071, 2017. [pdf reprint]

  6. Lu, G., S. A. Cummer, A. B. Chen, F. Lyu, D. Li, F. Liu, R.-R. Hsu, and H.-T. Su, Analysis of lightning strokes associated with sprites observed from space in North America, Terr. Atmos. Ocean. Sci, v. 28, p. 583, doi:10.3319/TAO.2017.03.31.01, 2017. [pdf reprint]

  7. Li, Y., C. Shen, Y. Xie, J. Li, W. Wang, S. A. Cummer, and Y. Jing, Tunable asymmetric transmission via lossy acoustic metasurfaces, Phys. Rev. Lett., v. 119, doi:10.1103/PhysRevLett.119.035501, 2017. [pdf reprint]

  8. Xie, Y., S. Ye, C. Reyes, P. Sithikong, B.-I. Popa, B. J. Wiley, and S. A. Cummer, Microwave metamaterials made by fused deposition 3D printing of a highly conductive copper-based filament, Appl. Phys. Lett., v. 110, doi:10.1063/1.4982718, 2017. [pdf reprint]

  9. Carvalho, F. L., M. A. Uman, D. M. Jordan, J. D. Hill, S. A. Cummer, D. A. Kotovsky, and R. C. Moore, Triggered lightning sky waves, return stroke modeling, and ionospheric effective height, J. Geophys. Res., v. 122, doi:10.1002/2016JD026202, 2017. [pdf reprint]


2016

  1. Wang, W., Y. Xie, B.-I. Popa, and S. A. Cummer, Subwavelength diffractive acoustics and wavefront manipulation with a reflective acoustic metasurface, J. Appl. Phys., v. 120, 195103, doi:10.1063/1.4967738, 2016. [pdf reprint]

  2. Barrett, J. P., A. R. Katko, and S. A. Cummer, Bandwidth tuning in transistor embedded metamaterials using variable resistance, PIER, v. 157, 49-61, 2016. [pdf reprint]

  3. Xie, Y., C. Shen, W. Wang, J. Li, D. Suo, B.-I. Popa, Y. Jing, and S. A. Cummer, Acoustic holographic rendering with two-dimensional metamaterial-based passive phased Array, Sci. Rep., v. 6, 35437, doi:10.1038/srep35437, 2016. [pdf reprint]

  4. Li, J., W. Wang, Y. Xie, B.-I. Popa, and S. A. Cummer, A sound absorbing metasurface with coupled resonators, Appl. Phys. Lett., v. 109, 091908, doi:10.1063/1.4961671, 2016. [pdf reprint]

  5. Lang, T. J., W. A. Lyons, S. A. Cummer, B. R. Fuchs, B. Dolan, S. A. Rutledge, P. Krehbiel, W. Rison, M. Stanley, and T. Ashcraft, Observations of two sprite-producing storms in Colorado, J. Geophys. Res., v. 121, doi:10.1002/2016JD025299, 2016. [pdf reprint]

  6. Lyu, F., S. A. Cummer, M. Briggs, M. Marisaldi, R. J. Blakeslee, E. Bruning, J. G. Wilson, W. Rison, P. Krehbiel, G. Lu, E. Cramer, G. Fitzpatrick. B. Mailyan, S. McBreen, O. J. Roberts, and M. Stanbro, Ground detection of terrestrial gamma ray flashes from distant radio signals, Geophys. Res. Lett., v. 43, doi:10.1002/2016GL070154, 2016. [pdf reprint]

  7. Barrett, J. P., A. R. Katko, and S. A. Cummer, Transistor-based metamaterials with dynamically tunable nonlinear susceptibility, Appl. Phys. Lett., v. 109, 061901, doi:10.1063/1.4960767, 2016. [pdf reprint]

  8. Hare, B., M. Uman, J. Dwyer, D. Jordan, M. Biggerstaff, J. Caicedo, F. Carvalho, R. Wilkes, D. Kotovsky, W. Gamerota, J. Pilkey, T. Ngin, R. Moore, H. Rassoul, S. A. Cummer, J. E. Grove, A. Nag, D. Betten, and A. Bozarth, Ground-level observation of a terrestrial gamma ray flash initiated by a triggered lightning, J. Geophys. Res., v. 121, doi:10.1002/2015JD024426, 2016. [pdf reprint]

  9. Lu, G., S. A. Cummer, Y. Tien, H. Zhang, F. Lyu, T. Wang, J. Yang, and W. A. Lyons, Sprite produced by consecutive impulse charge transfers in one negative stroke: observation and simulation, J. Geophys. Res., v. 121, doi:10.1002/2015JD024644, 2016. [pdf reprint]

  10. Mezentsev, A., N. Ostgaard, T. Gjesteland, K. Albrechtsen, M. Marisaldi, D. Smith, and S. A. Cummer, Radio emissions from double RHESSI TGFs, J. Geophys. Res., v. 121, doi:10.1002/2016JD025111, 2016. [pdf reprint]

  11. Popa, B.-I., W. Wang, A. Konneker, S. A. Cummer, C. A. Rohde, T. P. Martin, G. J. Orris, and M. D. Guild, Anisotropic acoustic metafluid for underwater operation, J. Acoustical Soc. America, v. 139, 3325, doi:10.1121/14950754, 2016. [pdf reprint]

  12. Shen, C., Y. Xie, J. Li, S. A. Cummer, and Y. Jing, Asymmetric acoustic transmission through near-zero-index and gradient-index metasurfaces, Appl. Phys. Lett., v. 108, 223502, doi:10.1063/1.4953264, 2016. [pdf reprint]

  13. Lyu, F., S. A. Cummer, G. Lu, X. Zhou, and J. Weinert, Imaging lightning intra-cloud initial stepped leaders by low frequency interferometric lightning mapping array, Geophys. Res. Lett., v. 43, doi:10.1002/2016GL069267, 2016. [pdf reprint]

  14. Liu, N., L. D. Boggs, and S. A. Cummer, Observation-constrained modeling of the ionospheric impact of negative sprites, Geophys. Res. Lett., v. 43, 2365-2373, doi:10.1002/2016GL068256, 2016. [pdf reprint]

  15. Popa, B.-I. and S. A. Cummer, Preserving omnidirectionality in optimized asymmetric transformation optics designs, Journal of Optics, v. 18, 044018, doi:10.1088/2040-8978/18/4/044018, 2016. [pdf reprint]

  16. Lin, X., H. Chen, T. Tyc, Y. Xie, and S. A. Cummer, Perfect conformal invisible device with feasible refractive indexes, Phys. Rev. B., v. 93, 041406, doi:10.1103/PhysRevB.93.041406, 2016. [pdf reprint]

  17. Kolmasova. I., O. Santolik, T. Farges, S. A. Cummer, R. Lan, and L. Uhlir, Sub-ionospheric propagation and peak currents of preliminary breakdown pulses before negative cloud-to-ground lightning discharges, Geophys. Res. Lett., v. 43, doi:10.1002/2015GL067364, 2016. [pdf reprint]

  18. Cummer, S. A., J. Christensen, and A. Alu, Controlling sound with acoustic metamaterials, Nature Reviews Materials, v. 1, 16001, doi:10.1038/natrevmats.2016.1, 2016. [pdf reprint]

  19. Boggs, L. D., N. Liu, M. Splitt, S. Lazarus, C. Glenn, H. Rassoul, and S. A. Cummer, An analysis of five negative sprite-parent discharges and their associated thunderstorm charge structures, J. Geophys. Res., doi:10.1002/2015JD024188, 2016. [pdf reprint]


2015

  1. McTague, L, S. A. Cummer. M. Briggs. V. Connaughton, M. Stanboro, and G. Fitzpatrick, A Lightning-Based Search for Nearby Observationally Dim Terrestrial Gamma-ray Flashes, J. Geophys. Res., v. 120, 12003-12017, doi:10.1002/2015JD023475, 2015. [pdf reprint]

  2. Shen, C., Y. Xie, N. Sui, W. Wang, S. A. Cummer, and Y. Jing, Broadband acoustic hyperbolic metamaterial, Phys. Rev. Lett., v. 115, 254301, doi:10.1103/PhysRevLett.115.254301, 2015. [pdf reprint]

  3. Somu, V. B., V. A. Rakov, M. A. Haddad, and S. A. Cummer, A study of changes in apparent ionospheric reflection height within individual lightning flashes, J. Atmos. Solar-Terrestrial Phys., doi:10.1016.j.jastp.2015.09.007, 2015. [pdf reprint]

  4. Cummer, S. A., F. Lyu, M. S. Briggs, G. Fitzpatrick, O. J. Roberts, and J. R. Dwyer, Lightning leader altitude progression in terrestrial gamma-ray flashes, Geophys. Res. Lett., doi:10.1002/2015GL065228, 2015. [pdf reprint]

  5. Lyu, F., S. A. Cummer, and L. McTague, Insights into high peak current in-cloud lightning events during thunderstorms, Geophys. Res. Lett., doi:10.1002/2015GL065047, 2015. [pdf reprint]

  6. Xie. Y., T.-H. Tsai, A. Konneker, B.-I. Popa, D. J. Brady, and S. A. Cummer, Single sensor multispeaker listening with acoustic metamaterials, Proceedings of the National Academy of Sciences, doi:10.1073/pnas.1502276112, 2015. [pdf reprint]

  7. Qin, J., V. P. Pasko, S. Celestin, S. A. Cummer, M. G. McHarg, and H. C. Stenbaek-Nielsen, Effects of phosphor persistence on high speed imaging of transient luminous events, IEEE Trans. Plasma Sci., v. 43, 2738, 2015. [pdf reprint]

  8. Popa, B.-I., A. Konneker, D.Shinde, and S. A. Cummer, Active acoustic metamaterials reconfigurable in real time, Physical Review B., v. 91, 220303, doi:10.1103/PhysRevB.91.220303, 2015. [pdf reprint]

  9. Lang, T. J., S. A. Cummer, D. Petersen, L. Flores-Rivera, W. A. Lyons. D. MacGorman, and W. Beasley, Large charge moment change lightning in the El Reno tornadic storm system, J. Geophys. Res., v. 120, doi:10.1002/2014JD022600, 2015. [pdf reprint]

  10. Barrett, J. P., and S. A. Cummer, Design and Full Characterization of Planar Active Magnetic RF Metamaterials, IEEE AWPL, doi:10.1109/LAWP.2014.2388431, 2015. [pdf reprint]

  11. Popa, B.-I., and S. A. Cummer, Negative refraction of sound in water-based metamaterials, Nature Materials, v. 14, doi:10.1038/nmat4253, 2015. [pdf reprint]

  12. Liu, N., N. Spiva, J. R. Dwyer, H. K. Rassoul, D. Free, and S. A. Cummer, Upward electrical discharges observed above tropical depression Dorian, Nature Communications, v. 6, 5995, doi:10.1038/ncomms6995, 2015. [pdf reprint]

  13. Yaniv, R. Y. Yair, C. Price, J. Bor, M. Sato, Y. Hobara, S. Cummer, J. Li, and A. Devir, Ground-based observations of the relations between lightning charge-moment-change and the physical and optical properties of column sprites, J. Atmos. Solar-Terrest. Phys, v. 107, doi:10.1016/j.jastp.2013.10.018, 2014. [pdf reprint]



2014

  1. Xie, Y., W. Wang, H. Chen, A. Konneker, B.-I. Popa, and S. A. Cummer, Wavefront modulation and subwavelength diffractive acoustics with an acoustic metasurface, Nature Communications, v. 5, 5553, doi:10.1038/ncomms6533, 2014. [pdf reprint]

  2. Lyu, F., S. A. Cummer, R. Solanki, J. Weinert, L. McTague, A. Katko, J. Barrett, and L. Zigoneanu, A low frequency near-field interferometric-TOA 3D lightning mapping array, Geophys. Res. Lett., doi:1002/2014GL061963, 2014. [pdf reprint]

  3. Cummer, S. A., M. S. Briggs, J. R. Dwyer, S. Xiong, V. Connaughton, G. J. Fishman, G. Lu, F. Lyu, and R. Solanki, The source altitude, electric current, and intrinsic brightness of terrestrial gamma-ray flashes, Geophys. Res. Lett., doi:10.1002/2014GL062196, 2014. [pdf reprint]

  4. Wang, W., Y. Xie, A. Konneker, B.-I. Popa, and S. A. Cummer, Design and demonstration of broadband thin planar diffractive acoustic lenses, Appl. Phys. Lett., v. 105, 101904, doi:10.1063/1.4895619, 2014. [pdf reprint]

  5. Liu, L., A. K. Katko, D. Li, and S. A. Cummer, Broadband electromagnetic metamaterials with reconfigurable fluid channels, Phys. Rev. B., v. 89, 245132, doi:10.1103/PhysRevB.89.245132, 2014. [pdf reprint]

  6. Beavis, N. K., T. J. Lang, S. A. Rutledge, W. A. Lyons, and S. A. Cummer, Regional, seasonal, and diurnal variations of cloud-to-ground lightning with large impulse charge moment changes, Monthly Weather Review, v. 142, 3666, doi:10.1175/MWR-D-14-00034.1, 2014. [pdf reprint]

  7. Katko, A. K., J. P. Barrett, and S. A. Cummer, Time-variant transistor-based metamaterial for tunability and efficient phase conjugation, J. Appl. Phys., v. 115, 144501, doi:10.1063/1.4871195, 2014. [pdf reprint]

  8. Zigoneanu, L., B.-I. Popa, and S. A. Cummer, Three-dimensional broadband omnidirectional acoustic ground cloak, Nature Materials, doi:10.1038/NMAT2901, 2014. [pdf reprint]

  9. Popa, B.-I. and S. A. Cummer, Non-reciprocal and highly nonlinear active acoustic metamaterials, Nature Communications, 5:3398, doi:10.1038/ncomms4398, 2014. [pdf reprint]

  10. Cummer, S. A., Selecting the direction of sound transmission, Science, v. 343, 495-496, doi:10.1126/science.1249616, 2014. [pdf reprint]


2013

  1. Marshall, T., M. Stolzenburg, S. Karunarathne, S. A. Cummer, G. Lu, H.-D. Betz, M. Briggs, V. Connaughton, and S. Xiong, Initial breakdown pulses in intracloud lightning flashes and their relation to terrestrial gamma ray flashes, J. Geophys. Res., v. 118, 10907-10925, doi:10.1002/jgrd.50866, 2013. [pdf reprint]

  2. Xie, Y., A. Konneker, B.-I. Popa, and S. A. Cummer, Tapered labyrinthine acoustic metamaterials for broadband impedance matching, Appl. Phys. Lett., v. 103, 201906, doi:10.1063/1.4831770, 2013. [pdf reprint]

  3. Hawkes, A. M., A. R. Katko, and S. A. Cummer, A microwave metamaterial with integrated power harvesting functionality, Appl. Phys. Lett., v. 103, 163901, doi:10.1063/1.4824473, 2013. [pdf reprint]

  4. Qin, J., S. Celestin, V. P. Pasko, S. A. Cummer, M. G. McHarg, and H. C. Stenbaek-Nielsen, Mechanism of column and carrot sprites derived from optical and radio observations, Geophys. Res. Lett., v. 40, 4777-4782, doi:10.1002/grl.50910, 2013. [pdf reprint]

  5. Lang, T. J., S. A. Cummer, W. A. Lyons, and S. A. Rutledge, The meteorology of negative cloud-to-ground lightning strokes with large charge moment changes: Implications for negative sprites, J. Geophys. Res., 118, 7886–7896, doi:10.1002/jgrd.50595, 2013. [pdf reprint]

  6. Popa, B.-I., L. Zigoneanu, and S. A. Cummer, Tunable active acoustic metamaterials, Phys. Rev. B, 88, 024303, doi:10.1103/PhysRevB.88.024303, 2013. [pdf reprint]

  7. Lu, G., S. A. Cummer, J. Li, L. Zigoneanu, W. A. Lyons, M. A. Stanley, W. Rison, P. R. Krehbiel, R. J. Thomas, S. Weiss, W. H. Beasley, R. G. Blakeslee, E. Bruning, D. R. MacGorman, S. Karunarathne, T. C. Marshall, K. Palivec, and T. Samaras, Coordinated observations of sprites and and in-cloud lightning flash structure, J. Geophys. Res, doi:10.1002/jgrd.50459, 2013. [pdf reprint]

  8. Dwyer, J. D. and S. A. Cummer, Radio emissions from terrestrial gamma-ray flashes, J. Geophys. Res., v. 118, 1–22, doi:10.1002/jgra.50188, 2013. [pdf reprint]

  9. Ostgaard, N., T. Gjesteland, B. E. Carlson, A. B. Collier, S. A. Cummer, G. Lu, and H. J. Christian, Simultaneous observations of optical lightning and terrestrial gamma ray flash from space, Geophys. Res. Lett, v. 40, 1–4, doi:/10.1002/grl.50466, 2013. [pdf reprint]

  10. Meyer, T., T. Lang, S. Rutledge, W. Lyons, S. A. Cummer, and G. Lu, Radar and lightning analyses of gigantic jet-producing storms, J. Geophys. Res., v. 118, 1–17, doi:10.1002/jgrd.50302, 2013. [pdf reprint]

  11. Cummer, S. A., W. A. Lyons, and M. A. Stanley, Three years of lightning impulse charge moment change measurements in the United States, J. Geophys. Res., v. 118, 1–14, doi:10.1002/jgrd.50442, 2013. [pdf reprint]

  12. Xie, Y., B.-I. Popa, L. Zigoneanu, and S. A. Cummer, Measurement of broadband negative index with space-coiling acoustic metamaterials, Phys. Rev. Lett., v. 110, 175501, doi:10.1103/PhysRevLett.110.175501, 2013. [pdf reprint]



2012

  1. Hager, W., R. Sonnenfeld, W. Feng, T. Kanmae, H. Stenbaek-Nielsen, M. McHarg, R. Haaland, S. A. Cummer, G. Lu, and J. Lapierre (2012), Charge rearrangement by sprites over a North Texas mesoscale convective system, J. Geophys. Res., v. 117, D22101, 2012. [pdf reprint]

  2. Li, D., L. Zigoneanu, B.-I. Popa, and S. A. Cummer (2012), Design of an acoustic metamaterial lens using genetic algorithms, Journal of the Acoustical Society of America, v. 132, 2823-2833. [pdf reprint]

  3. Li, J., S. A. Cummer, G. Lu, and L. Zigoneanu, Charge moment change and lightning-driven electric fields associated with negative sprites and halos, J. Geophys. Res., v. 117, A09310, 2012. [pdf reprint]

  4. Katko, A. R., G. Shvets, and S. A. Cummer, Phase conjugation metamaterials: particle design and imaging experiments, J. Optics, v. 14, 114003, doi:10.1088/2040-8978/14/11/114003, 2012. [pdf reprint]

  5. Haddad, M. A., V. A. Rakov, and S. A. Cummer, New measurements of lightning electric fields in Florida: Waveform characteristics, interaction with the ionosphere, and peak current estimates, Journal of Geophysical Research, v. 117, D10101, doi:10.1029/2011JD017196, 2012. [pdf reprint]

  6. Dwyer, J. R., D. M. Smith, and S. A. Cummer, High-energy atmospheric physics: terrestrial gamma-ray flashes and related phenomena, Space Science Review, doi: 10.1007/s11214-012-9894-0, 2012. [pdf reprint]

  7. Popa, B.-I. and S. A. Cummer, Nonreciprocal active metamaterials, Phys. Rev. B., v. 85, 205101, 2012. [pdf reprint]

  8. Lu, G., S. A. Cummer, R. J. Blakeslee, and E. McCaul, Lightning morphology and impulse charge moment changes of high peak current negative strokes (2012), J. Geophys. Res., v. 117, D04212. [pdf reprint]

  9. Li, J. and S. A. Cummer (2012), Relationship between sprite streamer behavior and lightning-driven electric fields, J. Geophys. Res., v. 117, A01317. [pdf reprint]


2011

  1. Katko, A. R., A. M. Hawkes, J. P. Barrett, and S. A. Cummer, Metamaterial RF limiter using PIN diodes, IEEE AWPL, v. 10, p. 1571, 2011. [pdf reprint]

  2. Smith, D. M., J. Dwyer, B. Hazelton, B. Greffenstette, G. F. M. Martinez-McKinney, Z. Y. Zhang, A. W. Lowell, N. A. Kelley, M. E. Splitt, S. M Lazarus, W. Ulrich, M. Schaal, Z. H. Saleh, E. Cramer, H. Rassoul, S. A. Cummer, G. Lu, X.-M. Shao, C. Ho, T. Hamlin, R. Blakeslee, and S. Heckman, A terrestrial gamma ray flash observed from an aircraft, J. Geophys. Res., v. 116, D20124, 2011. [pdf reprint]

  3. Neubert, T., O. Chanrion, E. Arnone, F. Zanotti, S. Cummer, J. Li, M. Fuellekrug, C. Haldoupis, and O. van der Velde, The properties of a gigantic jet reflected in a simultaneous sprite: Observations interpreted by a model (2011), J. Geophys. Res., v. 116, A12329. [pdf reprint]

  4. Zhai, Y., S. A. Cummer, J. L. Green, B. W. Reinisch, M. L, Kaiser, M. J. Reiner, and K. Goetz (2011), Magnetospheric radio tomographic imaging with IMAGE and WIND, J. Geophys. Res., v. 116, A12208. [pdf reprint]

  5. Popa, B.-I. and S. A. Cummer, Complex coordinates in transformation optics (2011), Phys. Rev. A, v. 84, 063837. [pdf reprint]

  6. Lang, T. J., Jingbo Li, W. A. Lyons, S. A. Cummer, S. A. Rutledge, and D. R. MacGorman (2011), Transient luminous events above two mesoscale convective systems: Charge moment change analysis, J. Geophys. Res., v. 116, A10306. [pdf reprint]

  7. Smith, D. M., J. Dwyer, B. Hazelton, B. Greffenstette, G. F. M. Martinez-McKinney, Z. Zhang, A. Lowell, N. Kelley, M. Splitt, S. Lazarus, W. Ulrich, M. Schaal, Z. Saleh, E. Cramer, H. Rassoul, S. A. Cummer, G. Lu, and R. Blakeslee (2011), The rarity of terrestrial gamma-ray flashes, Geophys. Res. Lett., v. 38, L08807. [pdf reprint]

  8. Cummer, S. A., G. Lu, M. S. Briggs, V. Connaughton, S. Xiong, G. J. Fishman, and J. R. Dwyer (2011), The lightning-TGF relationship on microsecond timescales, Geophys. Res. Lett., v. 38, L14810. [pdf reprint]

  9. Zigoneanu, L., B.-I. Popa, and S. A. Cummer (2011), Design and measurements of a broadband 2D acoustic lens, Phys. Rev. B., v84, 024305. [pdf reprint]

  10. Lu, G., S. A. Cummer, W. A. Lyons, P. R. Krehbiel, J. Li, W. Rison, R. J. Thomas, H. Edens, W. Beasley, M. A. Stanley, D. R. MacGorman, O. A. van der Velde, M. B. Cohen, T. J. Lang, and S. A. Rutledge (2011), Lightning development associated with two negative gigantic jets, Geophys. Res. Lett., v. 38, L12801. [pdf reprint]

  11. Han, F. and S. A. Cummer (2011), Daytime ionospheric D region sharpness derived from VLF radio atmospherics, J. Geophys. Res., v. 116, A05314. [pdf reprint]

  12. Popa, B.-I., L. Zigoneanu, and S. A. Cummer (2011), Experimental acoustic ground cloak in air, Phys. Rev. Lett., v. 106, 253901. [pdf reprint]

  13. Popa, B.-I. and S. A. Cummer (2011), Homogeneous and compact acoustic ground cloaks, Phys. Rev. B, v. 83, 224304. [pdf reprint]

  14. Lu, G., S. A. Cummer, J. Li, F. Han, D. M. Smith, and B. Grefenstette (2011), Characteristics of broadband magnetic lightning emissions associated with terrestrial gamma-ray flashes, J. Geophys. Res., v. 116, A03316. [pdf reprint]

  15. Zigoneanu, L., B.-I. Popa, A. Starr, and S. A. Cummer (2011), Design and measurements of a broadband 2D acoustic metamaterial with anisotropic effective mass density, J. Appl. Phys., v. 109, 054906. [pdf reprint]

  16. Thompson, R. T., S. A. Cummer, and J. Frauendiener (2011), Generalized transformation optics of linear materials, J. Optics, v. 13, 055105. [pdf reprint]

  17. Gamerota, W., J. Li, S. A. Cummer, H. Stenbaek-Nielsen, R. Haaland, and M. G. McHarg (2011), Comparison of sprite initiation altitudes between observations and models, J. Geophys. Res., v. 116, A02317. [pdf reprint]

  18. Li, J. and S. A. Cummer (2011), Estimation of electric charge in sprites from optical and radio observations, J. Geophys. Res., v. 116, A01301. [pdf reprint]

  19. Thompson, R. T., S. A. Cummer, and J. Frauendiener (2011), A completely covariant approach to transformation optics, Journal of Optics, v. 13, 024008. [pdf reprint]

  20. Cummer, S. A. and R. T. Thompson (2011), Frequency conversion by exploiting time in transformation optics, Journal of Optics, v. 13, 024007. [pdf reprint]


2010

  1. van der Velde, O. A., J. Bor, J. Li, S. A. Cummer, E. Arnone, F. Zanotti, M. Fullekrug, C. Haldoupis. S. N. Amor, and T. Farge (2010), Multi-instrumental observations of a positive gigantic jet producted by a winter thunderstorm in Europe, J. Geophys. Res., v. 115, D24301, doi:10.1029/2010JD014442. [pdf reprint]

  2. Rodger, C. J., B. R. Carson, S. A. Cummer, R. J. Gamble, M. A. Clilverd, J.-A. Sauvaud, M. Parrot, and J. C. Green (2010), Contrasting the efficiency of radiation belt losses caused by ducted and non-ducted whistler mode waves from ground-based transmitters, J. Geophys. Res., 115, A12208, doi:10.1029/2010JA015880. [pdf reprint]

  3. Sao Sabbas, F., P. D. Pautet, M. J. Taylor, M. Bailey, V. T. Rampinelli, N. Solorzano, H. Thomas, S. Cummer, R. H. Holzworth, O. Pinto, and N. J. Schuch (2010), Observations of Prolific Transient Luminous Event Production Above a Mesoscale Convective System in Argentina during the Sprite2006 Campaign in Brazil, J. Geophys. Res., 115, A00E58, doi:10.1029/2009JA014857. [pdf reprint]

  4. Han, F. and S. A. Cummer (2010), Midlatitude daytime D region ionosphere variability measured from radio atmospherics, J. Geophys. Res., v. 115, A10314, doi:10.1029/2010JA015715. [pdf reprint]

  5. Gu, S., J. P. Barrett, T. H. Hand, and S. A. Cummer (2010), A broadband low-reflection metamaterial absorber, J. Appl. Phys., v. 108, 064913. [pdf reprint]

  6. Popa, B.-I. and S. A. Cummer (2010), Layered transformation optics devices of arbitrary shape, Phys. Rev. A, v. 82, 033837. [pdf reprint]

  7. Sajuyigbe, S., M. Ross, P. Geren, S. A. Cummer, M. H. Tanelian, and D. R. Smith (2010), Wide angle impedance matching metamaterials for waveguide-fed phased array antennas, IET Microwaves, Antennas & Propagation, v. 4, pp. 1063-1072. [pdf reprint]

  8. Han, F. and S. A. Cummer (2010), Midlatitude nighttime D region ionosphere variability on hourly to monthly timescales, J. Geophys. Res., v. 115, A09323. [pdf reprint]

  9. Cohen, M. B., U. S. Inan, R. K. Said, M. S. Briggs, G. Fishman, V. Connaughton, and S. A. Cummer, A lightning discharge producing a relativistic electron beam, Geophys. Res. Lett., v. 37, L18806. [pdf reprint]

  10. Chou, J.-K., C. L. Kuo, L. Y. Tsai, A. B. Chen, H. T. Su, R. R. Hsu, S. A. Cummer, J. Li, H. U. Frey, S. B. Mende, Y, Takahashi, and L. C. Lee (2010), Gigantic jets with negative and positive polarity streamers, J. Geophys. Res., v. 115, A00E45. [pdf reprint]

  11. Katko, A. R., S. Gu, J. P. Barrett, B.-I. Popa, G. Shvets, and S. A. Cummer (2010), Phase conjugation and negative refraction using nonlinear active metamaterials, Phys. Rev. Lett., v. 105, 123905. [pdf reprint]

  12. Hand, T. H. and S. A. Cummer (2010), Reconfigurable Frequency Selective Surface Using Addressable Metamaterials, IEEE AWPL, v. 9, p. 70-74. [pdf reprint]

  13. Inan, U. S., S. A. Cummer, and R. A. Marshall (2010), A survey of ELF/VLF research on lightning-ionosphere interactions and causative discharges, J. Geophys. Res, 115, A00E36, doi:10.1029/2009JA014775. [pdf reprint]

  14. Lu, G., R. J. Blakeslee, J. Li, D. M. Smith, X.-M. Shao, E. W. McCaul, D. E. Buechler, H. J. Christian, J, M. Hall, and S. A. Cummer (2010), Lightning mapping observation of a terrestrial gamma-ray flash, Geophys. Res. Lett., 37, L11806. [pdf reprint]

  15. Lang, T. J., W. A. Lyons, S. A. Rutledge, J. Meyer, D. R. MacGorman, and S. A. Cummer (2010), Transient luminous events in two mesoscale convective systems: Storm structure and evolution, J. Geophys. Res., v. 115, A00E22, doi:10.1029/2009JA014500. [pdf reprint]

  16. Williams, E., W. Lyons, Y. Hobara, V. Mushtak, N. Asencio, R. Boldi, J. Bor, S. Cummer, E. Greenberg, M. Hayakawa, R. Holzworth, V. Kotroni, J. Li, C. Morales, T. Nelson, C. Price, B. Russell, G. Satori, K. Shirahata, Y. Takahashi, and K. Yamashita (2010), Ground-Based Detection of Sprites and their Parent Lightning Flashes over Africa during the AMMA Campaign, Quarterly Journal of the Royal Meteorological Society, v. 136, p. 257-271. [pdf reprint]

  17. Thomas, J. T., N. Solorzano, S. A. Cummer, and R. H. Holzworth (2010), Polarity and energetics of inner core lightning in three intense North Atlantic hurricanes, J. Geophys. Res., v. 115, A00E15, doi:10.1029/2009JA014777. [pdf reprint]


2009

  1. Popa, B.-I. and S. A. Cummer (2009), Design and characterization of broadband acoustic composite metamaterials, Physical Review B, v. 80, 174303. [pdf reprint]

  2. Adachi, T., S. A. Cummer, J. Li, Y. Takahashi, R.-R. Hsu, H.-T. Su, A. B. Chen, S. B. Mende, and H. U. Frey (2009), Estimating lightning current moment waveforms from satellite optical measurements, Geophys. Res. Lett., v. 36, L18808. [pdf reprint]

  3. Cummer, S. A., N. Kundtz, and B.-I. Popa (2009), General electromagnetic sources under coordinate transformations, Physical Review A, v. 80, 033820. [pdf reprint]

  4. Cummer, S. A., J. Li, F. Han, G. Lu, N. Jaugey, W. A. Lyons, and T. E. Nelson (2009), Quantification of the troposphere to ionosphere charge transfer in a gigantic jet, Nature Geoscience, v. 2, p. 617-620, doi:10.1038/ngeo607. [pdf reprint]

  5. Yuan, Y., B.-I. Popa, and S. A. Cummer (2009), Zero loss magnetic metamaterials using powered active unit cells, Optics Express, v. 17, p. 16135-16143. [pdf reprint]

  6. Farrell, W. M., J. J. Plaut, S. A. Cummer, D. A. Gurnett, G. Picardi, T. R. Watters, and A. Safaeinili (2009), Is the Martian water table hidden from radar view?, Geophys. Res. Lett., v. 36, L15206. [pdf reprint]

  7. Lu, G., S. A. Cummer, J. Li, F. Han, R. J. Blakeslee, and H. J. Christian (2009), Charge transfer and in-cloud structure of energetic positive cloud-to-ground lightning strokes, Geophys. Res. Lett., v. 36, L15805, doi:10.1029/2009GL038880. [pdf reprint]

  8. Popa, B.-I., J. Allen, and S. A. Cummer, Conformal array design with transformation electromagnetics, Applied Physics Letters, v. 94, 244102, 2009. [pdf reprint]

  9. Li, J. and S. A. Cummer, Measurements of sprite streamer acceleration and deceleration, Geophysical Research Letters, v. 36, L10812, doi:10.1029/2009GL037581, 2009. [pdf reprint]

  10. Allen, J., N. Kundtz, D. Roberts, S. A. Cummer, and D. R. Smith, Source transformations using superellipse equations, Applied Physics Letters, v. 94, 194101, 2009. [pdf reprint]

  11. Kuo, C.-L.., J. K. Chou, L. Y. Tsai, A. B. Chen, H. T. Su, R. R. Hsu, S. A. Cummer, H. U. Frey, S. B. Mende, Y. Takahashi, and L. C. Lee, Discharge processes, electric fields, and electron energy in ISUAL recorded gigantic jets, J. Geophys. Res., v. 114, A04314, doi:10.1029/2008JA013791, 2009. [pdf reprint]

  12. Hand, T. H., and S. A. Cummer, Controllable magnetic metamaterial using digitally addressable split ring resonators, IEEE AWPL, v. 8, doi: 10.1109/LAWP.2009.2012879, 2009. [pdf reprint]

  13. Zhai, Y., and S. A. Cummer, A fast tomographic reconstruction strategy for diffuse optical tomography, Optics Express, v. 17, 5298-5310, 2009. [pdf reprint]

  14. Cummer, S. A., R. Liu, and T.-J. Cui, A rigorous and practical approximate cloaking coordinate transformation, Journal of Applied Physics, v. 105, 056012, doi:10.1063/1.3080155, 2009. [pdf reprint]

  15. Popa, B.-I., and S. A. Cummer, Cloaking with optimized homogeneous anisotropic layers, Phys. Rev. A, v. 79, 023806, DOI: 10.1103/PhysRevA.79.023806, 2009. [pdf reprint]

  16. Hazelton, B. J., B. W. Grefenstette, D. M. Smith, J. R. Dwyer, X.-M. Shao, S. A. Cummer, T. Chronis, E. H. Lay, and R. H. Holzworth, The spectral dependence of terrestrial gamma-ray flashes on source distance, Geophys. Res. Lett., v. 36, L01108, doi: 10.1029/2008GL035906, 2009. [pdf reprint]


2008

  1. Kundtz, N., D. Roberts, J. Allen, S. A. Cummer, and D. R. Smith, Optical source transformations, Optics Express, v. 16, p. 21215, 2008. [pdf reprint]

  2. Cummer, S. A., M. Rahm, and D. Schurig, Material parameters and vector scaling in transformation acoustics, New J. Phys., v. 10, 115025, 2008. [pdf reprint]

  3. Hand, T. H., J. Gollub, S. Sajuyigbe, D. R. Smith, and S. A. Cummer, Characterization of complementary electric field resonator surfaces, Appl. Phys. Lett., v. 93, 212504, DOI: 10.1063/1.3037215, 2008. [pdf reprint]

  4. Yuan, Y, C. Bingham, T. Tyler, S. Palit, T. Hand. W. J. Padilla, N. M. Jokerst, and S. A. Cummer, A dual-resonant terahertz metamaterial based on single-particle electric-field-coupled resonators, Appl. Phys. Lett., v. 93, 191110, 2008. [pdf reprint]

  5. Ross, M., S. A. Cummer, T. K. Nielsen, and Y. Zhang, Simultaneous Remote Electric and Magnetic Field Measurements of Lightning Continuing Currents, J. Geophys. Res., 113, D20125, doi:10.1029/2008JD010294, 2008. [pdf reprint]

  6. Li, J., S. A. Cummer, W. A. Lyons, and T. E. Nelson, Coordinated analysis of delayed sprites with high speed images and remote electromagnetic fields, Journal of Geophysical Research, v. 113, D20206, doi:10.1029/2008JD010008, 2008. [pdf reprint]

  7. Lyons, W. A., S. A. Cummer, M. A. Stanley, K. C. Wiens, and T. E. Nelson, Supercells and sprites, Bulletin of the American Meteorological Society, p. 1165-1174, doi: 10.1175/BAMS2439.1, 2008. [pdf reprint]

  8. Erentok, A., R. W. Ziolkowski, J. A. Nielsen, R. B. Greegor, C. G. Parazzoli, M. H. Tanelian, S. A. Cummer, B.-I. Popa, T. Hand, D. C. Vier, and S. Schultz, Lumped element-based ENG, MNG, and DNG metamaterials at UHF frequencies, J. Applied Phys., v. 104, 034901, 2008. [pdf reprint]

  9. Taylor, M. J., M. A. Bailey, P. D. Pautet, S. A. Cummer, N, Jaugey, J, N. Thomas, N. N. Solorzano, F. Sao Sabbas, R. Holzworth, O. Pinto, and N. Schuch, Simultaneous imaging and ELF/VLF measurements of a sprite-halo driven by a negative lightning discharge over Argentina, Geophys. Res. Lett., v. 35, L14812, doi:10.1029/2008GL033984, 2008. [pdf reprint]

  10. Yuan, Y, S. Palit, C. Bingham, T. Hand. W. J. Padilla, D. R. Smith, N. M. Jokerst, and S. A. Cummer, Dual-band planar electric metamaterial in the terahertz range, Optics Express, v. 16, 9746Ð9752, 2008. [pdf reprint]

  11. Popa, B.-I. and S. A. Cummer, Compact dielectric particles as a building block for low loss magnetic metamaterials, Physical Review Letters, v. 100, 207401, 2008. [pdf reprint]

  12. Farrell, W. M., S. M. Clifford, S. M. Milkovich, C. J. Jeuschen, J. J. Plaut, G. Picardi, D. A. Gurnett, T. R. Watters, A. Safaeinili, A. B. Ivanov, R. J. Phillips, E. R. Stofan, E. Heggy, S. A. Cummer, and J. Espley, MARSIS subsurface radar investigations of the South Polar Reentrant Chasma Australe, Journal of Geophysical Research, v. 113, E04002, doi:10.1029/2007JE002974, 2008. [pdf reprint]

  13. Hand, T. H. and S. A. Cummer, Frequency tunable electromagnetic metamaterial using ferroelectric loaded split rings, Journal of Applied Physics, v. 103, 066105, 2008. [pdf reprint]

  14. Rahm, M., D. Schurig, D. A. Roberts, S. A. Cummer, D. R. Smith, J. B. Pendry, Design of electromagnetic cloaks and concentrators using form-invariant coordinate transformations of Maxwell's equations, Photonics and Nanostructures, vol. 6, pp. 87-95, 2008. [pdf reprint]

  15. Rahm, M., S. A. Cummer, D. Schurig, J. B. Pendry, and D. R. Smith, Optical design of reflectionless complex media by finite embedded coordinate transformations, Physical Review Letters, v. 100, 063903, 2008. [pdf reprint]

  16. Liu, R., Q. Cheng, T. Hand, J. J. Mock, T. J. Cui, S. A. Cummer, and D. R. Smith, Experimental Demonstration of Electromagnetic Tunneling Through an Epsilon Near Zero Metamaterial at Microwave Frequencies, Physical Review Letters, v. 100, 023903, 2008. [pdf reprint]

  17. Cummer, S. A., D. R. Smith, M. Rahm, J. Pendry, D. Schurig, and A. Starr, Scattering theory derivation of a 3D acoustic cloaking shell, Physical Review Letters, v. 100, 024301, 2008. [pdf reprint]

  18. Cummer, S. A., B.-I. Popa, and T. H. Hand, Q-based design equations for resonant metamaterials and experimental validation, IEEE Transactions on Antennas and Propagation., v. 56, p. 127, doi:10.1109/TAP.2007.912959, 2008. [pdf reprint]


2007

  1. Kuo, C.-L., A. B. Chen, L. Y. Tsai, R. K. Chou, R.-R. Hsu, H.-T. Su, L. C. Lee, S. A. Cummer, H. U. Frey, S. B. Mende, Y. Takahashi, and H. Fukunishi, Modeling elves observed by FORMOSAT-2 satellite, J. Geophys. Res., v. 112, A11312, doi:10.1029/2007JA012407, 2007. [pdf reprint]

  2. Erentok, A., R. W. Ziolkowski, J. A. Nielsen, R. B. Greegor, C. G. Parazzoli, M. H. Tanelian, S. A. Cummer, B.-I. Popa, T. Hand, D. C. Vier, and S. Schultz, Low frequency lumped element-based negative index metamaterial, Appl. Phys. Lett., v. 91, 184104, doi: 10.1063/1.2803771, 2007. [pdf reprint]

  3. Gollub, J., T. Hand, S. Sajuyigbe, S. Mendonca, S. Cummer, and D. R. Smith, Characterizing the effects of disorder in metamaterial structures, Appl. Phys. Lett., v. 91, 162907, doi: 10.1063/1.2801391, 2007. [pdf reprint]

  4. van der Velde, O. A., W. A. Lyons, S. A. Cummer, T. E. Nelson, and J. Bunnell, Analysis of the first gigantic jet recorded over continental North America, J. Geophys. Res., v. 112, D20104, doi:10.1029/2007JD008575, 2007. [pdf reprint]

  5. Frey, H. U., S. B. Mende, S. A. Cummer, J. Li, T. Adachi, H. Fukunishi, Y. Takahashi, A. B. Chen, R.-R. Hsu, H.-T. Su, and Y.-S. Chang, Halos generated by negative cloud-to-ground lightning, Geophys. Res. Lett., v. 34, L18801, doi: 10.1029/2007GL030908, 2007. [pdf reprint]

  6. Hand, T. H. and S. A. Cummer, Characterization of Tunable Metamaterial Elements Using MEMS Switches, IEEE Antennas and Wireless Propagation Letters, v. 6, p. 401, 2007. [pdf reprint]

  7. B.-I. Popa and S. A. Cummer, An architecture for active metamaterial particles and experimental validation at RF, Microwave and Optical Technology Letters, v. 49, p. 2574, 2007. [pdf reprint]

  8. Hu W., S. A. Cummer, and W. A. Lyons, Testing sprite initiation theory using lightning measurements and modeled EM fields, J. Geophys. Res., 112, D13115, doi:10.1029/2006JD007939, 2007. [pdf reprint]

  9. Cheng, Z., S. A. Cummer, R.-R. Hsu, and H. T. Su, Broadband VLF measurement of D region ionospheric perturbations caused by lightning electromagnetic pulses, J. Geophys. Res., 112, A06318, doi:10.1029/2006JA011840, 2007. [pdf reprint]

  10. Hand, T., S. A. Cummer, and N. Engheta, The measured electric field spatial distribution within a metamaterial subwavelength cavity resonator, IEEE Transactions on Antennas and Propagation, v. 55, p. 1781, 2007. [pdf reprint]

  11. Thomas, J. N., M. J. Taylor, D. Pautet, M. Bailey, N. Solorzano, R. Holzworth, M. McCarthy, M. Kokorowski, F. Sao Sabbas, O. Pinto, Jr., S. A. Cummer, N. Jaugey, J. Li, and N. J. Schuch, A very active sprite-producing storm observed over Argentina, EOS, v. 88, p. 117, 2007. [pdf reprint]

  12. Cummer, S. A., and D. Schurig, One path to acoustic cloaking, New Journal of Physics, v. 9, 45, 2007. [pdf reprint]


2006

  1. Farrell, W. M., J. R. Marshall, S. A. Cummer, G. T. Delory, and M. D. Desch, A model of the ULF magnetic and electric field generated from a dust devil, J. Geophys. Res., v. 111, E11004, doi:10.1029/2006JE002689, 2006. [pdf reprint]

  2. Schurig, D., J. J. Mock, B. J. Justice, S. A. Cummer, J. B. Pendry, A. Starr, and D. R. Smith, Demonstration of a metamaterial electromagnetic cloak at microwave frequencies, Science, v. 314, p. 977, 2006. [pdf reprint]

  3. Cummer, S. A., H. U. Frey, S. B. Mende, R. Hsu, H. Su, A. B. Chen, H. Fukunishi, and Y. Takahashi (2006), Simultaneous radio and satellite optical measurements of high-altitude sprite current and lightning continuing current, J. Geophys. Res., 111, A10315, doi:10.1029/2006JA011809. [pdf reprint]

  4. Cummer, S. A., B.-I. Popa, D. Schurig, D. R. Smith, and J. B. Pendry, Full-wave simulations of electromagnetic cloaking structures, Physical Review E, 74, 036621, 2006. [pdf reprint]

  5. Delory, G. T., W. M. Farrell, D. D. Sentman, N. O. Renno, S. K. Atreya, A.-S. Wong, S. A. Cummer, J. R. Marshall, S. C. R. Rafkin, and D. Catling, Oxidant Enhancement in Martian Dust Devils and Storms: Storm Electric Fields and Electron Dissociative Attachment, Astrobiology, v. 6, p. 451-462, 2006. [pdf reprint]

  6. Atreya, S. K., A. S. Wong, N. O. Renno, W. M. Farrell, G. T. Delory, D. Sentman, S. A. Cummer, J. Marshall, S. Rafkin, and D. Catling, Oxidant Enhancement in Martian Dust Devils and Storms: Implication for Life, and Habitability, Astrobiology, v. 6, p. 439-450, 2006. [pdf reprint]

  7. Zhai, Y., S. A. Cummer, and W. M. Farrell (2006), Quasi-electrostatic field analysis and simulation of Martian and terrestrial dust devils, J. Geophys. Res., 111, E06016, doi:10.1029/2005JE002618. [pdf reprint]

  8. Hu, W., and S. A. Cummer, An FDTD model for low and high altitude lightning-generated EM fields, IEEE Transactions on Antennas and Propagation, v. 54, p. 1513-1522, 2006. [pdf reprint]

  9. Xu, Y., S. A. Cummer, and W. M. Farrell (2006), Application of an orbital radar sounder model to detecting Martian polar subsurface features, J. Geophys. Res., 111, E06S17, doi:10.1029/2005JE002547. [pdf reprint]

  10. Cheng, Z., S. A. Cummer, D. N. Baker, and S. G. Kanekal, Nighttime D region electron density profiles and variability measured using broadband VLF energy from lightning, J. Geophys. Res., v. 111, A05302, doi:10.1029/2005JA011308, 2006. [pdf reprint]

  11. Zhai, Y. and S. A. Cummer, An orthogonal projection and regularization (OPR) technique for magnetospheric radio tomography, J. Geophys. Res., v. 111, A03207, doi:10.1029/2005JA011039, 2006. [pdf reprint]

  12. Cummer, S. A., N. Jaugey, J. Li, W. A. Lyons, T. E. Nelson, and E. A. Gerken, Submillisecond imaging of sprite development and structure, Geophys. Res. Lett., v. 33, L04104, doi:10.1029/2005GL024969, 2006. [pdf reprint]

  13. Popa, B.-I. and S. A. Cummer, Direct measurement of evanescent wave enhancement inside passive metamaterials, Physical Review E, v. 73, 016617, 2006. [pdf reprint]

  14. Farrell, W. M., N. Renno, G. T. Delory, S. A. Cummer, and J. R. Marshall, Integration of Electrostatic and Fluid Dynamics within a Dust Devil, J. Geophys. Res., v. 111, no. E1, E01006, doi: 10.1029/2005JE002527, 2006. [pdf reprint]


2005

  1. Popa, B.-I. and S. A. Cummer, Determining the effective electromagnetic properties of negative refractive index metamaterials from internal fields, Physical Review B, v. 72, 165102, 2005. [pdf reprint]

  2. Frey, H. U., S. B. Mende, S. A. Cummer, A. B. Chen, R.-R. Hsu, H.-T. Su, Y.-S. Chang, T. Adachi, H. Fukunishi, and Y. Takahashi, Beta-type stepped leader of elve-producing lightning, Geophysical Research Letters, v. 32, L13824, doi:10.1029/2005GL023080, 2005. [pdf reprint]

  3. Zhai, Y., and S. A. Cummer, A flexible and robust direct reconstruction method for magnetospheric radio tomography, Radio Science, vol. 40, no. 3, RS3004, doi: 10.1029/2004RS003100, 2005. [pdf reprint]

  4. Cummer, S. A., Y. Zhai, W. Hu, D. M. Smith, L. I. Lopez, and M. A. Stanley, Measurements and implications of the relationship between lightning and terrestrial gamma-ray flashes, Geophysical Research Letters, vol. 32, no. 8, L08811, doi:10.1029/2005GL022778, 2005. [pdf reprint]

  5. Cheng, Z. and S. A. Cummer, Broadband VLF measurements of lightning-induced ionospheric perturbations, Geophysical Research Letters, v. 32, L08804, doi:10.1029/2004GL022187, 2005. [pdf reprint]

  6. Cummer, S. A. and W. A. Lyons, Implications of lightning charge moment changes for sprite initiation, Journal of Geophysical Research, v. 110, A04304, doi: 10.1029/2004JA010812, 2005. [pdf reprint]


2004

  1. Cummer, S. A., and B.-I. Popa, Wave fields measured inside a negative refractive index metamaterial, Applied Physics Letters, v. 85, p. 4564-4566, 2004. [pdf reprint]

  2. Cummer, S. A., Perfectly Matched Layer Behavior in Negative Refractive Index Materials, IEEE Antennas and Wireless Propagation Letters, v. 3, p. 172-175, 2004. [pdf reprint]

  3. Hu, W., and S. A. Cummer, The Nearly Perfectly Matched Layer is a Perfectly Matched Layer, IEEE Antennas and Wireless Propagation Letters, v. 3, p. 137-140, 2004. [pdf reprint]

  4. Farrell, W. M, P. H. Smith, G. T. Delory, G. B. Hillard, J. R. Marshall, D. Catling, M. Hecht, D. M. Tratt, N. Renno, M. D. Desch, S. A. Cummer, J. G. Houser, and B. Johnson, Electric and magnetic signatures of dust devils from the 2000-2001 MATADOR desert tests, Journal of Geophysical Research, v. 109, doi: 10.1029/2003JE002088, 2004. [pdf reprint]

  5. Cummer, S. A., and W. A. Lyons, Lightning charge moment changes in U.S. High Plains thunderstorms, Geophysical Research Letters., v. 31, doi: 10.1029/2003GL019043, 2004. [pdf reprint]


2003

  1. Cummer, S. A., J. L. Green, B. W. Reinisch, S. F. Fung, M. L. Kaiser, J. S. Pickett, I. Christopher, R. Mutel, D. A. Gurnett, C. P. Escoubet, Advances in magnetospheric radio wave analysis and tomography, Advances in Space Research, v. 32, p. 329, 2003. [pdf reprint]

  2. Lyons, W. A., T. E. Nelson, E. R. Williams, S. A. Cummer, and M. A. Stanley, Characteristics of sprite-producing positive cloud-to-ground lightning during the 19 July 2000 STEPS mesoscale convective systems, Monthly Weather Review, v. 131, p. 2417, 2003. [pdf reprint]

  3. Farrell, W. M., G. T. Delory, S. A. Cummer and J. R. Marshall, A simple electrodynamic model of a dust devil, Geophysical Research Letters, v. 30, doi: 10.1029/2003GL017606, 2003. [pdf reprint]

  4. Cummer, S. A., Current moment in sprite-producing lightning, Journal of Atmospheric and Solar-Terrestrial Physics, v. 65, p. 499, 2003. [pdf reprint]

  5. Cummer, S. A., Dynamics of causal beam refraction in negative refractive index materials, Applied Physics Letters, v. 82, p. 2008, 2003. [pdf reprint]

  6. Cummer, S. A., A simple, nearly perfectly matched layer for general electromagnetic media, IEEE Microwave and Wireless Components Letters, v. 13, p. 128, 2003. [pdf reprint]

  7. Cummer, S. A., Simulated causal subwavelength focusing by a negative refractive index slab, Applied Physics Letters, v. 82, p. 1503, 2003. [pdf reprint]


2002

  1. Hu, W., S. A. Cummer, W. A. Lyons, and T. E. Nelson, Lightning charge moment changes for the initiation of sprites, Geophysical Research Letters, v. 29, no. 8, 1279, doi:10.1029/2001GL014593, 2002. [pdf reprint]


2001

  1. Ostgaard, N., J. Stadsnes, J. Bjordal, G. A. Germany, R. R. Vondrak, G. K. Parks. S. A. Cummer, D. L. Chenette, and J. G. Pronko, Auroral electron distributions derived from combined UV and X-ray emissions, Journal of Geophysical Research, v. 106, p. 26081, 2001. [pdf reprint]

  2. Cummer, S. A., M. J. Reiner, B. W. Reinisch, M. L. Kaiser, J. L. Green, R. F. Benson, R. Manning, and K. Goetz, A test of magnetospheric radio tomographic imaging with IMAGE and WIND, Geophysical Research Letters, v. 28, p. 1131, 2001. [pdf reprint]

  3. Cummer, S. A., and M. Fullekrug, Unusually intense continuing current in lightning produces delayed mesospheric breakdown, Geophysical Research Letters, v. 28, p. 495, 2001. [pdf reprint]


2000

  1. Cummer, S. A., Modeling electromagnetic propagation in the Earth-ionosphere waveguide, IEEE Transactions on Antennas and Propagation, v. 48, p. 1420, 2000. [pdf reprint]

  2. Cummer, S. A., and U. S. Inan, Ionospheric E region remote sensing with ELF radio atmospherics, Radio Science, v. 35, p. 1437, 2000. [pdf reprint]

  3. Ostgaard, N., J. Stadsnes, J. Bjordal, R. R. Vondrak, S. A. Cummer, D. L. Chenette, M. Schulz, and J. G. Pronko, Cause of the localized maximum of X-ray emission in the morning sector: A comparison with electron measurements, Journal of Geophysical Research, v. 105, p. 20869, 2000. [pdf reprint]

  4. Ostgaard, N., J. Stadsnes, J. Bjordal, R. R. Vondrak, S. A. Cummer, D. L. Chenette, M. Schulz, G. K. Parks, M. J. Brittnacher, D. L. McKenzie, and J. G. Pronko, Global X-ray emission during an isolated substorm: A case study, Journal of Atmospheric and Terrestrial Physics, v. 62, p. 889, 2000. [pdf reprint]

  5. Gjerloev, J. W., E. Friis-Christensen, R. A. Hoffman, and S. A. Cummer, The Harang discontinuity in auroral substorms, Magnetospheric Current Systems, AGU Geophysical Monograph 118, p. 209, 2000.

  6. Cummer, S. A., R. R. Vondrak, R. F. Pfaff, J. W. Gjerloev, C. W. Carlson, R. E. Ergun, W. J. Peria, R. C. Elphic, R. J. Strangeway, J. B. Sigwarth, L. A. Frank, Auroral surge currents and electrodynamics with FAST and VIS, Magnetospheric Current Systems, AGU Geophysical Monograph 118, p. 191, 2000. [pdf reprint]

  7. Cummer, S. A., and U. S. Inan, Modeling ELF radio atmospheric propagation and extracting lightning currents from ELF observations, Radio Science, v. 35, p. 385, 2000. [pdf reprint]

  8. Stanley, M., M. Brook, P. Krehbiel, and S. A. Cummer, Detection of daytime sprites via a unique sprite ELF signature, Geophysical Research Letters, v. 27, p. 875, 2000. [pdf reprint]

  9. Cummer, S. A., R. R. Vondrak, N. Ostgaard, J. Stadsnes, J. Bjordal, D. L. Chenette, M. J. Brittnacher, G. K. Parks, J. B. Sigwarth, L. A. Frank, Global multispectral auroral imaging of an isolated substorm, Geophysical Research Letters, v. 27, p. 637, 2000. [pdf reprint]


1999

  1. Barrington-Leigh, C. P., U. S. Inan, M. Stanley, and S. A. Cummer, Sprites triggered by negative lightning discharges, Geophysical Research Letters, v. 26, p. 3605, 1999. [pdf reprint]

  2. Cummer, S. A., and M. Stanley, Submillisecond resolution lightning currents and sprite development: Observations and implications, Geophysical Research Letters, v. 26, p. 3205, 1999. [pdf reprint]

  3. Cummer, S. A., and W. M. Farrell, Radio atmospheric propagation on Mars and potential remote sensing applications, Journal of Geophysical Research, v. 104, p. 14149, 1999. [pdf reprint]

  4. Ostgaard, N., J. Stadsnes, J. Bjordal, R. R. Vondrak, S. A. Cummer, D. L. Chenette, G. K. Parks, M. J. Brittnacher, and D. L. McKenzie, Global scale electron precipitation features seen in UV and x-rays during substorms, Journal of Geophysical Research, v. 104, p. 10191, 1999. [pdf reprint]

  5. Farrell, W. M., M. L. Kaiser, M. D. Desch, J. G. Houser, S. A. Cummer, D. M. Wilt, and G. A. Landis, Detecting electrical activity from martian dust storms, Journal of Geophysical Research, v. 104, p. 3795, 1999. [pdf reprint]


1998

  1. Cummer, S. A., U. S. Inan, and T. F. Bell, Ionospheric D region remote sensing using VLF radio atmospherics, Radio Science, v. 33, p. 1781, 1998. [pdf reprint]

  2. Foster, J. C., S. A. Cummer, and U. S. Inan, Mid-latitude particle and electric field effects at the onset of the November 1993 geomagnetic storm, Journal of Geophysical Research, v. 103, p. 26359, 1998. [pdf reprint]

  3. Cummer, S. A., U. S. Inan, T. F. Bell, and C. P. Barrington-Leigh, ELF radiation produced by electrical currents in sprites, Geophysical Research Letters, v. 25, p. 1281, 1998. [pdf reprint]


1997

  1. Cummer, S. A. and U. S. Inan, Measurement of charge transfer in sprite-producing lightning using ELF radio atmospherics, Geophysical Research Letters, v. 24, p. 1731, 1997. [pdf reprint]

  2. Kelley, M. C., S. D. Baker, R. H. Holzworth, P. Argo, and S. A. Cummer, LF and MF observations of the lightning electromagnetic pulse at ionospheric altitudes, Geophysical Research Letters, v. 24, p. 1111, 1997. [pdf reprint]

  3. Cummer, S. A., T. F. Bell, U. S. Inan, and D. L. Chenette, VLF remote sensing of high energy auroral particle precipitation, Journal of Geophysical Research, v. 102, p. 7477, 1997. [pdf reprint]

  4. Cummer, S. A., An analysis of new and existing FDTD methods for isotropic cold plasma and a method for increasing their accuracy, IEEE Transactions on Antennas and Propagation, v. 45, p. 392, 1997. [pdf reprint]


1996

  1. Cummer, S. A., T. F. Bell, U. S. Inan, and L. J. Zanetti, VLF remote sensing of the auroral electrojet, Journal of Geophysical Research, v. 101, p. 5381, 1996. [pdf reprint]


1995

  1. Bell T. F., U. S. Inan, M. T. Danielson, and S. A. Cummer, VLF signatures of ionospheric heating by HIPAS, Radio Science, v. 30, p. 1855, 1995. [pdf reprint]