Quantifying ground state entanglement of the BCS model
Quantum Physics
2009-11-10 v2 Strongly Correlated Electrons
High Energy Physics - Theory
Abstract
The concept of local concurrence is used to quantify the entanglement between a single qubit and the remainder of a multi-qubit system. For the ground state of the BCS model in the thermodynamic limit the set of local concurrences completely describe the entanglement. As a measure for the entanglement of the full system we investigate the Average Local Concurrence (ALC). We find that the ALC satisfies a simple relation with the order parameter. We then show that for finite systems with fixed particle number, a relation between the ALC and the condensation energy exposes a threshold coupling. Below the threshold, entanglement measures besides the ALC are significant.
Cite
@article{arxiv.quant-ph/0411032,
title = {Quantifying ground state entanglement of the BCS model},
author = {Clare Dunning and Jon Links and Huan-Qiang Zhou},
journal= {arXiv preprint arXiv:quant-ph/0411032},
year = {2009}
}
Comments
5 pages, 3 figures. V2: added new results & discussion on crossover regime