Wallraff A, Schuster D I, Blais A, Frunzio L, Majer J, Devoret M H, Girvin S M, Schoelkopf R J
Department of Applied Physics, Yale University, New Haven, Connecticut 06520, USA.
Phys Rev Lett. 2005 Aug 5;95(6):060501. doi: 10.1103/PhysRevLett.95.060501. Epub 2005 Aug 1.
In a Rabi oscillation experiment with a superconducting qubit we show that a visibility in the qubit excited state population of more than 95% can be attained. We perform a dispersive measurement of the qubit state by coupling the qubit non-resonantly to a transmission line resonator and probing the resonator transmission spectrum. The measurement process is well characterized and quantitatively understood. In a measurement of Ramsey fringes, the qubit coherence time is larger than 500 ns.
在一个使用超导量子比特的拉比振荡实验中，我们表明可以实现量子比特激发态布居数超过95%的可见度。我们通过将量子比特非共振地耦合到传输线谐振器并探测谐振器的传输光谱，对量子比特状态进行色散测量。测量过程得到了很好的表征并且可以定量理解。在拉姆齐条纹测量中，量子比特的相干时间大于500纳秒。
