Quantum information dynamics in a high-dimensional parity-time-symmetric system

0534015 - ÚJF 2021 RIV US eng J - Journal Article
Bian, Z. - Xiao, L. - Wang, K. - Onanga, F. A. - Růžička, František - Yi, W. - Joglekar, Y. N. - Xue, P.
Quantum information dynamics in a high-dimensional parity-time-symmetric system.
Physical Review A. Roč. 102, č. 3 (2020), č. článku 030201. ISSN 2469-9926. E-ISSN 2469-9934
Institutional support: RVO:61389005
Keywords : PT symmetry * exceptional points * dynamics
OECD category: Atomic, molecular and chemical physics (physics of atoms and molecules including collision, interaction with radiation, magnetic resonances, Mössbauer effect)
Impact factor: 3.140, year: 2020
Method of publishing: Limited access
https://doi.org/10.1103/PhysRevA.102.030201

Non-Hermitian systems with parity-time (PT) symmetry give rise to exceptional points (EPs) with exceptional properties that arise due to the coalescence of eigenvectors. Such systems have been extensively explored in the classical domain, where second- or higher-order EPs have been proposed or realized. In contrast, quantum information studies of PT-symmetric systems have been confined to systems with a two-dimensional Hilbert space. Here, by using a single-photon interferometry setup, we simulate the quantum dynamics of a four-dimensional PT-symmetric system across a fourth-order exceptional point. By tracking the coherent, nonunitary evolution of the density matrix of the system in PT-symmetry unbroken and broken regions, we observe the entropy dynamics for both the entire system, and the gain and loss subsystems. Our setup is scalable to the higher-dimensional PT-symmetric systems, and our results point towards the rich dynamics and critical properties.
Permanent Link: http://hdl.handle.net/11104/0312234