论文标题
检测泵探针光谱中挤压声子
Detection of squeezed phonons in pump-probe spectroscopy
论文作者
论文摘要
声子在光学激发固体中挤压状态的强大工程已成为控制和操纵其特性的有前途的工具。但是，与量子光学系统相反，声子挤压的检测是微妙而难以捉摸的，一个重要的问题是什么构成了它的明确特征。艺术的状态涉及观察振荡的时间两倍，时间是时间频率的频率分辨出均衡声子波动的测量值。使用Keldysh形式主义，我们表明这样的信号是挤压声子的必要签名，但不是足够的签名，因为我们确定了几种不涉及挤压的机制，并且会产生类似的振荡。我们表明，可靠的检测需要时间和频率解决声子光谱函数的测量。
Robust engineering of phonon squeezed states in optically excited solids has emerged as a promising tool to control and manipulate their properties. However, in contrast to quantum optical systems, detection of phonon squeezing is subtle and elusive, and an important question is what constitutes an unambiguous signature of it. The state of the art involves observing oscillations at twice the phonon frequency in time resolved measurements of the out of equilibrium phonon fluctuation. Using Keldysh formalism we show that such a signal is a necessary but not a sufficient signature of a squeezed phonon, since we identify several mechanisms that do not involve squeezing and yet which produce similar oscillations. We show that a reliable detection requires a time and frequency resolved measurement of the phonon spectral function.
