Departamento de Matemática Aplicada, Universidad de Granada, Fuentenueva s/n, 18071 Granada, Spain.
J Phys Condens Matter. 2014 Dec 3;26(48):485005. doi: 10.1088/0953-8984/26/48/485005. Epub 2014 Oct 29.
We study coherence and entanglement properties of the state space of a composite bi-fermion (two electrons pierced by λ magnetic flux lines) at one Landau site of a bilayer quantum Hall system. In particular, interlayer imbalance and entanglement (and its fluctuations) are analyzed for a set of U(4) coherent (quasiclassical) states generalizing the standard pseudospin U(2) coherent states for the spin-frozen case. The interplay between spin and pseudospin degrees of freedom opens new possibilities with regard to the spin-frozen case. Actually, spin degrees of freedom make interlayer entanglement more effective and robust under perturbations than in the spin-frozen situation, mainly for a large number of flux quanta λ. Interlayer entanglement of an equilibrium thermal state and its dependence with temperature and bias voltage is also studied for a pseudo-Zeeman interaction.
我们研究了双层量子霍尔系统中一个朗道能级上复合双费米子（被 λ 磁通量线穿透的两个电子）的状态空间的相干和纠缠性质。特别是，对于一组 U(4)相干（准经典）态，我们分析了层间不平衡和纠缠（及其波动），这些态推广了自旋冻结情况下的标准赝自旋 U(2)相干态。自旋和赝自旋自由度之间的相互作用为自旋冻结情况提供了新的可能性。实际上，自旋自由度使得在扰动下，层间纠缠比在自旋冻结情况下更有效和稳健，主要是对于大量的磁通量量子 λ。我们还研究了赝塞曼相互作用下平衡热态的层间纠缠及其与温度和偏置电压的关系。
