Jordan Andrew N, Korotkov Alexander N, Büttiker Markus
Department of Physics and Astronomy, University of Rochester, New York 14627, USA.
Phys Rev Lett. 2006 Jul 14;97(2):026805. doi: 10.1103/PhysRevLett.97.026805.
A kicked quantum nondemolition measurement is introduced, where a qubit is weakly measured by pumping current. Measurement statistics are derived for weak measurements combined with single-qubit unitary operations. These results are applied to violate a generalization of the Leggett-Garg inequality. The violation is related to the failure of the noninvasive detector assumption, and may be interpreted as either intrinsic detector backaction, or the qubit entangling the microscopic detector excitations. The results are discussed in terms of a quantum point contact kicked by a pulse generator, measuring a double quantum dot.
我们引入了一种受激量子非破坏测量，其中通过注入电流对量子比特进行弱测量。推导了与单量子比特酉操作相结合的弱测量的测量统计量。这些结果被用于违反莱格特 - 加格不等式的一种推广形式。这种违反与非侵入性探测器假设的失效有关，并且可以被解释为要么是探测器的固有反作用，要么是量子比特与微观探测器激发的纠缠。我们根据由脉冲发生器驱动的量子点接触测量双量子点的情况来讨论这些结果。
