Evidence Hub

PT -symmetric, non-Hermitian quantum many-body physics—a methodological perspective

V. Meden, L. Grunwald, D. Kennes

Reports on progress in physics. Physical Society, 2023

41 citations

Abstract

We review the methodology to theoretically treat parity-time- ( PT -) symmetric, non-Hermitian quantum many-body systems. They are realized as open quantum systems with PT symmetry and couplings to the environment which are compatible. PT -symmetric non-Hermitian quantum systems show a variety of fascinating properties which single them out among generic open systems. The study of the latter has a long history in quantum theory. These studies are based on the Hermiticity of the combined system-reservoir setup and were developed by the atomic, molecular, and optical physics as well as the condensed matter physics communities. The interest of the mathematical physics community in PT -symmetric, non-Hermitian systems led to a new perspective and the development of the elegant mathematical formalisms of PT -symmetric and biorthogonal quantum mechanics, which do not make any reference to the environment. In the mathematical physics research, the focus is mainly on the remarkable spectral properties of the Hamiltonians and the characteristics of the corresponding single-particle eigenstates. Despite being non-Hermitian, the Hamiltonians can show parameter regimes, in which all eigenvalues are real. To investigate emergent quantum many-body phenomena in condensed matter physics and to make contact to experiments one, however, needs to study expectation values of observables and correlation functions. One furthermore, has to investigate statistical ensembles and not only…

Read the paper

Related studies

Go deeper in Evidence Hub

Evidence Hub adds a study data sheet (design, sample size, evidence level, key numbers), an AI summary and a chat grounded in the paper's text.

Open this study Sign up free