We address the discrimination of structured baths at different temperatures by dephasing quantum probes. We derive the exact reduced dynamics and evaluate the minimum error probability achievable by three different kinds of quantum probes, namely, a qubit, a qutrit, and a quantum register made of two qubits. Our results indicate that dephasing quantum probes are useful in discriminating low values of temperature and that lower probabilities of error are achieved for intermediate values of the interaction time, where the minimum probability of error scales as $1/2N$, with $N$ the number of energy levels of the probe. A qutrit probe outperforms a qubit one in the discrimination task, whereas entangled probes show smaller optimal times.

中文翻译：

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用量子相移探针区分欧姆热浴

我们通过移相量子探针来解决在不同温度下结构化浴的区别。我们导出精确的降阶动力学，并评估三种不同类型的量子探针（即量子位，量子态和由两个量子位组成的量子寄存器）可获得的最小错误概率。我们的结果表明，相移量子探针可用于区分温度的低值，并且对于相互作用时间的中间值，可以实现较低的错误概率，其中最小错误概率为$\mathrm{1个}/2ñ$，带有 $ñ$探针的能级数。在区分任务中，qutrit探针的性能优于qubit探针，而纠缠的探针显示的最佳时间更短。