Enhancing the detection of natural thermal entanglement with disorder.
Phys Rev Lett 102:10 (2009) 100503
Abstract:
Physical systems have some degree of disorder present in them. We discuss how to treat natural, thermal entanglement in any random macroscopic system from which a thermodynamic witness bounded by a constant can be found. We propose that functional many-body perturbation theory be applied to allow either a quenched or an annealed average over the disorder to be taken. We find, when considering the example of an XX Heisenberg spin chain with a random coupling strength, that the region of natural entanglement detected by both witnesses can be enhanced by the disorder.Detection and engineering of spatial mode entanglement with ultra-cold bosons
(2009)
Quantum instability and edge entanglement in the quasi-long-range order
Physical Review A - Atomic, Molecular, and Optical Physics 79:2 (2009)
Abstract:
We investigate the buildup of quasi-long-range order in the XX chain with a transverse magnetic field at finite size. As the field is varied, the ground state of the system displays multiple level crossings producing a sequence of entanglement jumps. Using the partial fidelity and susceptibility, we study the transition to the thermodynamic limit and argue that the topological order can be described in terms of kink-antikink pairs and marked by edge spin entanglement. © 2009 The American Physical Society.Entanglement and nonlocality of a single relativistic particle
(2009)