论文标题
使用杂质探针强相关的费米量量子系统的热度法
Thermometry of Strongly Correlated Fermionic Quantum Systems using Impurity Probes
论文作者
论文摘要
我们将量子杂质模型研究为量子温度计的平台。单个量子自旋-1/2杂质与我们称为环境或浴室的显式，结构化的典型热环境耦合。当杂质与环境耦合为ISING或临近交换类型时，我们批判性地评估了杂质的温度值。在ISIN情况下，我们发现敏感性等效于理想化的两级系统，峰温度性能在温度下在应用的控制场中线性缩放，与耦合强度和环境光谱特征无关。相比之下，由于可以发展出强探针 - 环境纠缠，因此可以实现较丰富的温度响应。在低温下，我们发现具有通用温度响应的制度，该响应独立于微观细节，仅由环境的低能光谱特征控制。在此制度中发展的多体纠缠意味着具有弱应用控制场的低温温度固有敏感性较小，而通过用更强的场抑制纠缠纠缠来恢复最佳灵敏度。
We study quantum impurity models as a platform for quantum thermometry. A single quantum spin-1/2 impurity is coupled to an explicit, structured, fermionic thermal environment which we refer to as the environment or bath. We critically assess the thermometric capabilities of the impurity as a probe, when its coupling to the environment is of Ising or Kondo exchange type. In the Ising case, we find sensitivity equivalent to that of an idealized two-level system, with peak thermometric performance obtained at a temperature that scales linearly in the applied control field, independent of the coupling strength and environment spectral features. By contrast, a richer thermometric response can be realized for Kondo impurities, since strong probe-environment entanglement can then develop. At low temperatures, we uncover a regime with a universal thermometric response that is independent of microscopic details, controlled only by the low-energy spectral features of the environment. The many-body entanglement that develops in this regime means that low-temperature thermometry with a weakly applied control field is inherently less sensitive, while optimal sensitivity is recovered by suppressing the entanglement with stronger fields.
