Department of Physics, University of California, Berkeley, 94720, USA.
Phys Rev Lett. 2012 Aug 3;109(5):050506. doi: 10.1103/PhysRevLett.109.050506.
We demonstrate high-fidelity, quantum nondemolition, single-shot readout of a superconducting flux qubit in which the pointer state distributions can be resolved to below one part in 1000. In the weak excitation regime, continuous measurement permits the use of heralding to ensure initialization to a fiducial state, such as the ground state. This procedure boosts readout fidelity to 93.9% by suppressing errors due to spurious thermal population. Furthermore, heralding potentially enables a simple, fast qubit reset protocol without changing the system parameters to induce Purcell relaxation.
我们演示了一种高保真度、量子非破坏性、单-shot 的超导磁通量子比特读出方法，其中指针状态分布可以分辨到低于 1000 分之一。在弱激发态下，连续测量允许使用标志来确保初始化到基准状态，如基态。通过抑制由于虚假热态引起的错误，这种方法将读出保真度提高到 93.9%。此外，标志可能会启用一种简单、快速的量子比特重置协议，而无需更改系统参数来诱导普塞尔弛豫。
