Berry Phases and Quantum Phase Transitions

Alioscia Hamma

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Berry Phases and Quantum Phase Transitions

Alioscia Hamma

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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.

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Alioscia Hamma. 2006-02-10. Berry Phases and Quantum Phase Transitions. https://arxiv.org/abs/quant-ph/0602091

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