Department of Chemistry, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada.
Phys Rev Lett. 2013 May 31;110(22):223002. doi: 10.1103/PhysRevLett.110.223002. Epub 2013 May 29.
We determine the phase diagram of a polaron model with mixed breathing-mode and Su-Schrieffer-Heeger couplings and show that it has two sharp transitions, in contrast to pure models which exhibit one (for Su-Schrieffer-Heeger coupling) or no (for breathing-mode coupling) transition. We then show that ultracold molecules trapped in optical lattices can be used as a quantum simulator to study precisely this mixed Hamiltonian, and that the relative contributions of the two couplings can be tuned with external electric fields. The parameters of current experiments place them in the region where one of the transitions occurs. We also propose a scheme to measure the polaron dispersion using stimulated Raman spectroscopy.
我们确定了一个具有混合呼吸模式和 Su-Schrieffer-Heeger 耦合的极化子模型的相图，并表明它有两个急剧的转变，与只表现出一个（对于 Su-Schrieffer-Heeger 耦合）或没有（对于呼吸模式耦合）转变的纯模型形成对比。然后我们表明，被困在光学晶格中的超冷分子可以用作量子模拟器来精确地研究这个混合哈密顿量，并且两个耦合的相对贡献可以通过外部电场来调节。当前实验的参数使它们处于发生转变的区域之一。我们还提出了一种使用受激拉曼光谱测量极化子色散的方案。
