Quantum computing and condensed matter physics with microwave photons

Time-reversal symmetrization of spontaneous emission for quantum state transfer

Srikanth J. Srinivasan, Neereja M. Sundaresan, Darius Sadri, Yanbing Liu, Jay M. Gambetta, Terri Yu, S. M. Girvin, and Andrew A. Houck

We demonstrate the ability to control the spontaneous emission from a superconducting qubit coupled to a cavity. The time domain profile of the emitted photon is shaped into a symmetric truncated exponential. The experiment is enabled by a qubit coupled to a cavity, with a coupling strength that can be tuned in tens of nanoseconds while maintaining a constant dressed state emission frequency. Symmetrization of the photonic wave packet will enable use of photons as flying qubits for transfering the quantum state between atoms in distant cavities.