Wang H, Hofheinz M, Ansmann M, Bialczak R C, Lucero E, Neeley M, O'Connell A D, Sank D, Wenner J, Cleland A N, Martinis John M
Department of Physics, University of California, Santa Barbara, California 93106, USA.
Phys Rev Lett. 2008 Dec 12;101(24):240401. doi: 10.1103/PhysRevLett.101.240401. Epub 2008 Dec 8.
We demonstrate the controlled generation of Fock states with up to 15 photons in a microwave coplanar waveguide resonator coupled to a superconducting phase qubit. The subsequent decay of the Fock states, due to dissipation, is then monitored by varying the time delay between preparing the state and performing a number-state analysis. We find that the decay dynamics can be described by a master equation where the lifetime of the n-photon Fock state scales as 1/n, in agreement with theory. We have also generated a coherent state in the microwave resonator, and monitored its decay process. We demonstrate that the coherent state maintains a Poisson distribution as it decays, with an average photon number that decreases with the same characteristic decay time as the one-photon Fock state.
我们展示了在与超导相位量子比特耦合的微波共面波导谐振器中可控地产生多达15个光子的福克态。随后，由于耗散导致的福克态衰减，通过改变制备态与进行数态分析之间的时间延迟来进行监测。我们发现，衰减动力学可以用一个主方程来描述，其中n光子福克态的寿命按1/n缩放，这与理论相符。我们还在微波谐振器中产生了一个相干态，并监测了其衰减过程。我们证明，相干态在衰减时保持泊松分布，其平均光子数以与单光子福克态相同的特征衰减时间减少。
