Photonic quantum simulations of coupled <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mi mathvariant="script">PT</mml:mi></mml:math>-symmetric Hamiltonians
Nicola Maraviglia, Patrick Yard, Ross Wakefield, Jacques Carolan, Chris Sparrow, Levon Chakhmakhchyan, C. Harrold, Toshikazu Hashimoto, Nobuyuki Matsuda, Andrew K. Harter, Yogesh N. Joglekar, Anthony Laing
Abstract
Parity-time-symmetric ($\mathcal{PT}$-symmetric) Hamiltonians are generally non-Hermitian and give rise to exotic behavior in quantum systems at exceptional points, where eigenvectors coalesce. The recent realization of $\mathcal{PT}$-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 composed of twin pairs of $\mathcal{PT}$-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 behavior 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.