Coulomb analogy for nonhermitian degeneracies near quantum phase transitions

Abstract

Degeneracies near the real axis in a complex-extended parameter space of a hermitian Hamiltonian are studied. We present a method to measure distributions of such degeneracies on the Riemann sheet of a selected level and apply it in classification of quantum phase transitions. The degeneracies are shown to behave similarly as complex zeros of a partition function.

4 pages

References in corpus (1)

• Continuous unitary transformations in two-level boson systems

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