近日，日本国立情报学研究所的Hiroo Azuma及其研究团队取得一项新进展。他们揭示了双光子Jaynes-Cummings模型对热噪声的不敏感性。相关研究成果已于2024年12月17日在国际知名学术期刊《物理评论A》上发表。

该研究团队采用热场动力学（TFD）方法，研究了多光子Jaynes-Cummings模型（JCM）的热效应。设定多光子JCM整个系统的初始状态，为原子基态与有限温度下腔场相干态的乘积，并计算了其随时间的变化。研究人员评估了拉比振荡坍缩与恢复的周期，以及低温展开至二阶扰动下原子的相干相对熵。

结果表明，通过直观估算得出的周期与TFD扰动理论的结果高度吻合。特别地，研究人员发现两光子JCM的周期，几乎不依赖于腔场相干态的振幅或温度。数值计算显示，即使对于非零温度情况，两光子JCM的相干相对熵也随时间推移而不衰减。相比之下，单光子、三光子和四光子JCM的相干相对熵，在零温度和有限温度情况下均随时间推移而衰减。

附：英文原文

Title: Insensitivity of the two-photon Jaynes-Cummings model to thermal noise

Author: Hiroo Azuma

Issue&Volume: 2024/12/17

Abstract: We study the thermal effects of the multiphoton Jaynes-Cummings model (JCM) using a thermofield dynamics (TFD) method. Letting the initial state of the whole system for the multiphoton JCM be a product of the ground state of an atom and a coherent state of a cavity field at finite temperature, we compute its time evolution. We evaluate a period of the collapse and revival of the Rabi oscillations and the relative entropy of coherence of the atom up to the second-order perturbation of the low-temperature expansion. We show that an intuitive estimation of the period matches the result of the perturbation theory of TFD well. In particular, we see that the period of the two-photon JCM hardly depends on the amplitude of the coherent state of the cavity field or the temperature. Numerical calculations suggest that the relative entropy of coherence of the two-photon JCM does not decay even for nonzero-temperature cases as time proceeds. By contrast, the relative entropies of coherence for single-, three-, and four-photon JCMs decay as time proceeds for zero- and finite-temperature cases.

DOI: 10.1103/PhysRevA.110.063714

Source: https://journals.aps.org/pra/abstract/10.1103/PhysRevA.110.063714