Universal noise in continuous transport measurements of interacting fermions
Universal noise in continuous transport measurements of interacting fermions
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DOI：
10.1103/physreva.98.063619
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发表时间：
2018-02
影响因子：
2.9
通讯作者：
S. Uchino;Masahito Ueda;J. Brantut
中科院分区：
文献类型：
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作者：
S. Uchino;Masahito Ueda;J. Brantut
我们提出并分析了在光腔中使用色散探测的原子序数和原子电流的连续测量。对于一个封闭系统中的原子数测量，我们将探测噪声和测量反作用引起的加热速率与Tan接触联系起来，并在良腔极限下确定了一个涌现的普适量子非破坏（QND）机制。然后，我们表明，这样一个连续的QND测量的原子数作为量子限制的电流传感器在两端设置。我们推导出一个普遍的边界上的电流测量的精度，这是从检测噪声和原子电流测量的反作用之间的权衡结果。无论相互作用的强度或物质的状态如何，我们的结果都适用，并为冷原子量子模拟器中输运性质的未来精确测量设定了基本界限。
We propose and analyze continuous measurements of atom number and atomic currents using dispersive probing in an optical cavity. For an atom-number measurement in a closed system, we relate both the detection noise and the heating rate due to measurement back-action to Tan's contact, and identify an emergent universal quantum non-demolition (QND) regime in the good-cavity limit. We then show that such a continuous QND measurement of atom number serves as a quantum-limited current transducer in a two-terminal setup. We derive a universal bound on the precision of current measurement, which results from a tradeoff between detection noise and back-action of the atomic current measurement. Our results apply regardless of the strength of interaction or the state of matter and set fundamental bounds on future precision measurements of transport properties in cold-atom quantum simulators.