Photonic quantum simulations of coupled $PT$-symmetric Hamiltonians

Abstract

Parity-time ($PT$) symmetric Hamiltonians are generally non-Hermitian and give rise to exotic behaviour in quantum systems at exceptional points, where eigenvectors coalesce. The recent realisation of $PT$-symmetric Hamiltonians in quantum systems has ignited efforts to simulate and investigate many-particle quantum systems across exceptional points. Here we use a programmable integrated photonic chip to simulate a model comprised of twin pairs of $PT$-symmetric Hamiltonians, with each the time reverse of its twin. We simulate quantum dynamics across exceptional points including two- and three-particle interference, and a particle-trembling behaviour that arises due to interference between subsystems undergoing time-reversed evolutions. These results show how programmable quantum simulators can be used to investigate foundational questions in quantum mechanics.

15 pages, 7 figures

References in corpus (6)

• Making Sense of Non-Hermitian Hamiltonians
• Microwave photonics with superconducting quantum circuits
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• Non-Hermitian Ring Laser Gyroscopes with Enhanced Sagnac Sensitivity
• The Naimark dilated PT-symmetric brachistochrone
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