近日，桂林航天工业学院徐春玲团队研究了温度的色散量子位读出。这一研究成果发表在2025年6月9日出版的《物理评论A》杂志上。
压缩光可以指数级地提高色散量子比特读出的信噪比（SNR），特别是使用注入外部压缩（IES）和腔内压缩（ICS）的组合。课题组进一步研究了IES和ICS是否也可以指数级提高温度的测量精度。在完全热化的量子比特与热浴隔离的情况下，当温度、测量时间或输入光子数接近0时，温度的测量精度可以呈指数级提高。
一般来说，热波动会阻止压缩光的作用。当多个量子位与热浴保持相互作用时，如果腔的损耗率较大，并且量子位和光学腔之间的耦合足够弱，则可以实现海森堡缩放。同时，IES还可以进一步促进温度测量精度的指数级提高。
附：英文原文
Title: Dispersive qubit readout of temperature
Author: Dong Xie, Chunling Xu
Issue&Volume: 2025/06/09
Abstract: Squeezed light can exponentially increase the signal-to-noise ratio (SNR) of dispersive qubit readout, especially using a combination of injected external squeezing (IES) and intracavity squeezing (ICS). We further investigate whether IES and ICS can also exponentially improve the measurement precision of temperature. In the case of fully thermalized qubits isolated from a thermal bath, the measurement precision of temperature can be improved exponentially when the temperature, the measurement time, or the input photon number approaches 0. In general, thermal fluctuations prevent the action of squeezed light. When multiple qubits maintain interacting with the thermal bath, the Heisenberg scaling can be achieved if the loss rate of the cavity is large and the coupling between the qubit and the optical cavity is weak enough. In the meantime, IES can also further promote the improvement of the measurement precision of the temperature exponentially.
DOI: 10.1103/PhysRevA.111.062412
Source: https://journals.aps.org/pra/abstract/10.1103/PhysRevA.111.062412
