Sous J, Chakraborty M, Adolphs C P J, Krems R V, Berciu M
Department of Physics and Astronomy, University of British Columbia, Vancouver, British, Columbia, V6T 1Z1, Canada.
Stewart Blusson Quantum Matter Institute, University of British Columbia, Vancouver, British, Columbia, V6T 1Z4, Canada.
Sci Rep. 2017 Apr 26;7(1):1169. doi: 10.1038/s41598-017-01228-y.
We study two identical fermions, or two hard-core bosons, in an infinite chain and coupled to phonons by interactions that modulate their hopping as described by the Peierls/Su-Schrieffer-Heeger (SSH) model. We show that exchange of phonons generates effective nearest-neighbor repulsion between particles and also gives rise to interactions that move the pair as a whole. The two-polaron phase diagram exhibits two sharp transitions, leading to light dimers at strong coupling and the flattening of the dimer dispersion at some critical values of the parameters. This dimer (quasi)self-trapping occurs at coupling strengths where single polarons are mobile. This illustrates that, depending on the strength of the phonon-mediated interactions, the coupling to phonons may completely suppress or strongly enhance quantum transport of correlated particles.
我们研究了处于无限链中且通过如Peierls/Su-Schrieffer-Heeger（SSH）模型所描述的调制其跳跃的相互作用与声子耦合的两个相同费米子或两个硬核玻色子。我们表明，声子的交换在粒子之间产生有效的最近邻排斥作用，并且还引发使粒子对作为一个整体移动的相互作用。双极化子相图呈现出两个尖锐的转变，在强耦合时导致轻二聚体，并且在参数的某些临界值处二聚体色散变平。这种二聚体（准）自陷发生在单极化子可移动的耦合强度处。这表明，取决于声子介导的相互作用的强度，与声子的耦合可能会完全抑制或强烈增强相关粒子的量子输运。
