Berry Phases and Quantum Phase Transitions
Quantum Physics
2007-05-23 v1 Other Condensed Matter
Abstract
We study the connection between Berry phases and quantum phase transitions of generic quantum many-body systems. Consider sequences of Berry phases associated to sequences of loops in the parameter space whose limit is a point. If the sequence of Berry phases does not converge to zero, then the limit point is a quantum critical point. Quantum critical points are associated to failures of adiabaticity. We discuss the remarkable example of the anisotropic XY spin chain in a transverse magnetic field and detect the XX region of criticality.
Cite
@article{arxiv.quant-ph/0602091,
title = {Berry Phases and Quantum Phase Transitions},
author = {Alioscia Hamma},
journal= {arXiv preprint arXiv:quant-ph/0602091},
year = {2007}
}