论文标题
量子气体中的射频响应和杂质接触
Radio-frequency response and contact of impurities in a quantum gas
论文作者
论文摘要
我们研究了在有限温度下与量子气相互作用的杂质的射频光谱。在单个杂质的限制下，我们使用费米的黄金法则表明，将杂质引入（或注射）杂质等同于弹出最初与介质相互作用的杂质，因为“注入”和“弹性”光谱响应仅与频率的指定函数相互关联。因此，注射光谱响应中包含量子杂质的完整光谱信息，可以使用一系列理论方法（包括变异方法）确定。我们使用此特性来计算费米极化子的状态和棕褐色接触的有限温度方程。我们接触移动杂质的结果与最近的实验非常吻合，我们发现与无限杂质质量相比，有限温度的行为在质量上有所不同。
We investigate the radio-frequency spectroscopy of impurities interacting with a quantum gas at finite temperature. In the limit of a single impurity, we show using Fermi's golden rule that introducing (or injecting) an impurity into the medium is equivalent to ejecting an impurity that is initially interacting with the medium, since the "injection" and "ejection" spectral responses are simply related to each other by an exponential function of frequency. Thus, the full spectral information for the quantum impurity is contained in the injection spectral response, which can be determined using a range of theoretical methods, including variational approaches. We use this property to compute the finite-temperature equation of state and Tan contact of the Fermi polaron. Our results for the contact of a mobile impurity are in excellent agreement with recent experiments and we find that the finite-temperature behavior is qualitatively different compared to the case of infinite impurity mass.
