Vodola Davide, Lepori Luca, Ercolessi Elisa, Gorshkov Alexey V, Pupillo Guido
IPCMS (UMR 7504) and ISIS (UMR 7006), Université de Strasbourg and CNRS, 67000 Strasbourg, France and Dipartimento di Fisica, Università di Bologna and INFN, Via Irnerio 46, 40126 Bologna, Italy.
IPCMS (UMR 7504) and ISIS (UMR 7006), Université de Strasbourg and CNRS, 67000 Strasbourg, France.
Phys Rev Lett. 2014 Oct 10;113(15):156402. doi: 10.1103/PhysRevLett.113.156402. Epub 2014 Oct 9.
We propose and analyze a generalization of the Kitaev chain for fermions with long-range p-wave pairing, which decays with distance as a power law with exponent α. Using the integrability of the model, we demonstrate the existence of two types of gapped regimes, where correlation functions decay exponentially at short range and algebraically at long range (α > 1) or purely algebraically (α < 1). Most interestingly, along the critical lines, long-range pairing is found to break conformal symmetry for sufficiently small α. This is accompanied by a violation of the area law for the entanglement entropy in large parts of the phase diagram in the presence of a gap and can be detected via the dynamics of entanglement following a quench. Some of these features may be relevant for current experiments with cold atomic ions.
我们提出并分析了具有长程p波配对的费米子的Kitaev链的一种推广形式，其随着距离以幂律形式衰减，指数为α。利用该模型的可积性，我们证明了存在两种能隙区域，其中关联函数在短程呈指数衰减，在长程呈代数衰减（α>1）或纯代数衰减（α<1）。最有趣的是，沿着临界线，对于足够小的α，发现长程配对会破坏共形对称性。这伴随着在存在能隙的情况下，相图大部分区域中纠缠熵的面积律被违反，并且可以通过猝灭后的纠缠动力学检测到。其中一些特征可能与当前冷原子离子实验相关。
