1. J. Y. Qiu, A. Grimsmo, K. Peng, B. Kannan, B. Lienhard, Y. Sung, P. Krantz, V. Bolkhovsky, G. Calusine, D. Kim, A. Melville, B. M. Niedzielski, J. Yoder, M. E. Schwartz, T. P. Orlando, I. Siddiqi, S. Gustavsson, K. P. O'Brien, W. D. Oliver, "Broadband Squeezed Microwaves and Amplification with a Josephson Traveling-Wave Parametric Amplifier" arXiv:2201.11261, 1-29 (2022)
  2. M. Naghiloo, K. Peng, Y. Ye, G. Cunningham, K. P. O'Brien. "Broadband Microwave Isolation with Adiabatic Mode Conversion in Coupled Superconducting Transmission Lines" arXiv:2103.07793 (2021)


  1. K. Peng, M. Naghiloo, J. Wang, G. D. Cunningham, Y. Ye, and K. P. O’Brien "Floquet-Mode Traveling-Wave Parametric Amplifiers" PRX Quantum 3, 020306 (2022)
  2. A. Hashim, R. K. Naik, A. Morvan, J.-L. Ville, B. Mitchell, J. M. Kreikebaum, M. Davis, E. Smith, C. Iancu, K. P. O’Brien, I. Hincks, J. J. Wallman, J. Emerson, and I. Siddiqi, "Randomized Compiling for Scalable Quantum Computing on a Noisy Superconducting Quantum Processor" Phys. Rev. X 11, 041039, 1-12 (2021).
  3. Y. Ye, K. Peng, M. Naghiloo, G. Cunningham, K. P. O'Brien. "Engineering Purely Nonlinear Coupling Using a Quarton" Phys. Rev. Lett. 127, 050502 (2021)
  4. A. Morvan, V. V. Ramasesh, M. S. Blok, J.M. Kreikebaum, K. O'Brien, L. Chen, B. K. Mitchell, R. K. Naik, D. I. Santiago, I. Siddiqi. "Qutrit Randomized Benchmarking" Phys. Rev. Lett. 126, 210504 (2021)
  5. A. Grimsmo, B. Royer, J. M. Kreikebaum, Y. Ye, K. O'Brien, I. Siddiqi, A. Blais. "Quantum Metamaterial for Broadband Detection of Single Microwave Photons" Phys. Rev. Applied 15, 034074 (2021)
  6. M. S. Blok, V. V. Ramasesh, T. Schuster, K. O'Brien, J.M. Kreikebaum, D. Dahlen, A. Morvan, B. Yoshida, N. Y. Yao, I. Siddiqi. "Quantum Information Scrambling on a Superconducting Qutrit Processor" Phys. Rev. X 11, 021010 (2021)
  7. J. M. Kreikebaum, K. P. O'Brien, A. Morvan, I. Siddiqi. "Improving wafer-scale Josephson junction resistance variation in superconducting quantum coherent circuits." Supercond. Sci. Technol. 33 06LT02 (2020) doi:10.1088/1361-6668/ab8617
  8. B. Lienhard, J. Braumüller, W. Woods, D. Rosenberg, G. Calusine, S. Weber, A. Vepsäläinen, K. O'Brien, T. P. Orlando, S. Gustavsson, W. D. Oliver. "Microwave Packaging for Superconducting Qubits." Proceedings of the 2019 IEEE/MTT-S International Microwave Symposium (2019) arXiv:1906.05425
  9. L.M. Procopio, L. A. Rozema, Z. J. Wong, D. R. Hamel, K. O'Brien, X. Zhang, B. Dakić, and P. Walther. "Single-photon test of hyper-complex quantum theories using a metamaterial." Nat. Comm. 8, 15044 (2017) doi:10.1038/ncomms15044
  10. Z. J. Wong*, Y. Xu*, J. Kim*, K. O'Brien, Y. Wang, L. Feng, and X. Zhang. "Lasing and anti-lasing in a single cavity." Nat. Phot. 10, 796-801 (2016). doi:10.1038/nphoton.2016.216
  11. S. S. Kruk, Z. J. Wong, E. Pshenay-Severin, K. O'Brien, D. Neshev, and Y. S. Kivshar, and X. Zhang. "Magnetic hyperbolic optical metamaterials." Nat. Comm. 7 11329 (2016) doi:10.1038/ncomms11329
  12. K. O'Brien, C. Macklin, D. Hover, M. E. Schwartz, V. Bolkhovsky, X. Zhang, W. D. Oliver, I. Siddiqi. "Towards quantum-noise limited multiplexed microwave readout of qubits" Proceedings of the 2016 IEEE/MTT-S International Microwave Symposium (2016)doi:10.1109/MWSYM.2016.7540350
  13. F. J. Diaz, T. Hatakeyama, J. Rho, Y. Wang, K. O'Brien, X. Zhang, C. M. de Sterke, B. T. Kuhlmey, and S. Palomba. "Sensitive method for measuring third order nonlinearities in compact dielectric and hybrid plasmonic waveguides." Opt. Express 24, 545-554 (2016). doi:10.1364/OE.24.000545
  14. C. Macklin, K. O'Brien, D. Hover, M. E. Schwartz, V. Bolkhovsky, X. Zhang, W. D. Oliver, I. Siddiqi. "A near-quantum-limited Josephson traveling-wave parametric amplifier." Science 350, 307-310 (2015). doi:10.1126/science.aaa8525
  15. M. Mrejen*, H. Suchowski*, T. Hatakeyama*, C. Wu, L. Feng, K. O'Brien, Y. Wang, X. Zhang. "Adiabatic elimination-based coupling control in densely packed subwavelength waveguides." Nat. Comm. 6, 7565 (2015). doi:10.1038/ncomms8565
  16. K. O'Brien*, H. Suchowski*, J. Rho, A. Salandrino, B. Kanté, X. Yin, X. Zhang. "Predicting nonlinear properties of metamaterials from the linear response." Nat. Mat. 14, 379-383 (2015). doi:10.1038/nmat4214
  17. S. N. David, Y. Zhai, A. M. van der Zande, K. O'Brien, P. Y. Huang, D. A. Chenet, J. C. Hone, X. Zhang, and X. Yin. "Rapid, all-optical crystal orientation imaging of two-dimensional transition metal dichalcogenide monolayers." Appl. Phys. Lett. 107, 111902 (2015). doi:10.1063/1.4930232
  18. K. O'Brien, C. Macklin, I. Siddiqi, X. Zhang. "Resonant Phase Matching of Josephson Junction Traveling Wave Parametric Amplifiers." Phys. Rev. Lett. 113, 157001 (2014). doi:10.1103/PhysRevLett.113.157001
  19. Z. Ye*, T. Cao*, K. O'Brien, H. Zhu, X. Yin, Y. Wang, S. G. Louie, X. Zhang. "Probing excitonic dark states in single-layer tungsten disulphide." Nature 513, 214-218 (2014). doi:10.1038/nature13734
  20. K. O'Brien*, N. D. Lanzillotti-Kimura*, J. Rho, H. Suchowski, X. Yin, X. Zhang. "Ultrafast acousto-plasmonic control and sensing in complex nanostructures." Nat. Comm. 5, 4042 (2014). doi:10.1038/ncomms5042
  21. X. Yin*, Z. Ye*, D. A. Chenet*, Y. Ye*, K. O'Brien, J. C. Hone, X. Zhang. "Edge Nonlinear Optics on a MoS2 Atomic Monolayer." Science 344, 488-490 (2014). doi:10.1126/science.1250564
  22. H. Suchowski*, K. O'Brien*, Z. J. Wong*, A. Salandrino, X. Yin, X. Zhang. "Phase Mismatch-Free Nonlinear Propagation in Optical Zero-Index Materials." Science 342, 1223-1226 (2013). doi:10.1126/science.1244303
  23. B. Kanté, Y. Park, K. O'Brien, D. Shuldman, N. D. Lanzillotti-Kimura, Z. J. Wong, X. Yin, X. Zhang. "Symmetry breaking and optical negative index of closed nanorings." Nat. Comm. 3, 1180 (2012). doi:10.1038/ncomms2161
  24. K. O'Brien, N. D. Lanzillotti-Kimura, H. Suchowski, B. Kanté, Y. Park, X. Yin, X. Zhang. "Reflective interferometry for optical metamaterial phase measurements." Opt. Lett. 37, 4089-4091 (2012). doi:10.1364/OL.37.004089
  25. B. Kanté, K. O'Brien, A. Niv, X. Yin, X. Zhang. "Proposed isotropic negative index in three-dimensional optical metamaterials." Phys. Rev. B 85, 041103 (2012). doi:10.1103/PhysRevB.85.041103


  1. Y. Ye. "Nonlinearity engineering with the Quarton." S.M. thesis. Massachusetts Institute of Technology (2020) Link
  2. K. Peng. "Quantum efficiency of Josephson traveling wave parametric amplifiers with many-Mode processes." S.M. thesis. Massachusetts Institute of Technology (2020) Link
  3. K. O'Brien. "Nonlinear Light-Matter Interactions in Metamaterials." University of California, Berkeley (2016) Link