Endo Suguru, Matsuzaki Yuichiro, Kakuyanagi Kosuke, Saito Shiro, Lambert Neill, Nori Franco
Theoretical Quantum Physics Laboratory, Cluster for Pioneering Research, RIKEN, 351-0198, Wako-shi, Japan.
National Institute of Advanced Industrial Science and Technology AIST, Tsukuba Central 2, Umezono 1-1-1, Tsukuba, Ibaraki, 305-8568, Japan.
Sci Rep. 2020 Feb 4;10(1):1751. doi: 10.1038/s41598-019-56866-1.
We explore the problem of projecting the ground-state of an ultra-strong-coupled circuit-QED system into a non-energy-eigenstate. As a measurement apparatus we consider a nonlinear driven resonator. We find that the post-measurement state of the nonlinear resonator exhibits a large correlation with the post-measurement state of the ultra-strongly coupled system even when the coupling between measurement device and system is much smaller than the energy scales of the system itself. While the projection is imperfect, we argue that because of the strong nonlinear response of the resonator it works in a practical regime where a linear measurement apparatus would fail.
我们探讨了将超强耦合电路量子电动力学（circuit-QED）系统的基态投影到非能量本征态的问题。作为测量装置，我们考虑一个非线性驱动谐振器。我们发现，即使测量装置与系统之间的耦合远小于系统本身的能量尺度，非线性谐振器的测量后状态与超强耦合系统的测量后状态仍表现出很大的相关性。虽然这种投影并不完美，但我们认为，由于谐振器的强非线性响应，它在实际情况下能够工作，而线性测量装置在此情况下会失效。
