A Unified View on Geometric Phases and Exceptional Points in Adiabatic Quantum Mechanics

Abstract

We present a formal geometric framework for the study of adiabatic quantum mechanics for arbitrary finite-dimensional non-degenerate Hamiltonians. This framework generalizes earlier holonomy interpretations of the geometric phase to non-cyclic states appearing for non-Hermitian Hamiltonians. We start with an investigation of the space of non-degenerate operators on a finite-dimensional state space. We then show how the energy bands of a Hamiltonian family form a covering space. Likewise, we show that the eigenrays form a bundle, a generalization of a principal bundle, which admits a natural connection yielding the (generalized) geometric phase. This bundle provides in addition a natural generalization of the quantum geometric tensor and derived tensors, and we show how it can incorporate the non-geometric dynamical phase as well. We finish by demonstrating how the bundle can be recast as a principal bundle, so that both the geometric phases and the permutations of eigenstates can be expressed simultaneously by means of standard holonomy theory.

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• The physics of exceptional points
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• Geometric Phase for Non-Hermitian Hamiltonians and Its Holonomy Interpretation
• Bloch vector, disclination and exotic quantum holonomy
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Cited by in corpus (4)

• Exponential sensitivity revival of noisy non-Hermitian quantum sensing with two-photon drives
• Real energies and Berry phases in all PT-regimes in time-dependent non-Hermitian theories
• Topological adiabatic dynamics in classical mass-spring chains with clamps
• Frames of group-sets and their application in bundle theory