Stable States with Non-Zero Entropy under Broken $\mathcal{P}\mathcal{T}$-Symmetry

Abstract

The $\mathcal{P}\mathcal{T}$-symmetric non-Hermitian systems have been widely studied and explored both in theory and in experiment these years due to various interesting features. In this work, we focus on the dynamical features of a triple-qubit system, one of which evolves under local $\mathcal{P}\mathcal{T}$-symmetric Hamiltonian. A new kind of abnormal dynamic pattern in the entropy evolution process is identified, which presents a parameter-dependent stable state, determined by the non-Hermiticity of Hamiltonian in the broken phase of $\mathcal{P}\mathcal{T}$-symmetry. The entanglement and mutual information of a two-body subsystem can increase beyond the initial values, which do not exist in the Hermitian and two-qubit $\mathcal{P}\mathcal{T}$-symmetric systems. Moreover, an experimental demonstration of the stable states in non-Hermitian system with non-zero entropy and entanglement is realized on a four-qubit quantum simulator with nuclear spins. Our work reveals the distinctive dynamic features in the triple-qubit $\mathcal{P}\mathcal{T}$-symmetric system and paves the way for practical quantum simulation of multi-party non-Hermitian system on quantum computers.

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Cited by in corpus (10)

• Speeding up entanglement generation by proximity to higher-order exceptional points
• Experimental demonstration of coherence flow in $\mathcal{P}\mathcal{T}$- and anti-$\mathcal{P}\mathcal{T}$-symmetric systems
• Entanglement Dynamics in Anti-$\mathcal{P}\mathcal{T}$-Symmetric Systems
• Extension of Noether's theorem in PT-symmetric systems and its experimental demonstration in an optical setup
• Controlling NMR spin systems for quantum computation
• Imaginary gap-closed points and dynamics in a class of dissipative systems
• Experimental demonstration of the dynamics of quantum coherence evolving under a PT-symmetric Hamiltonian on an NMR quantum processor
• Scattering of the asymmetric ${\varphi }^6$ kinks from a $\mathcal{P}\mathcal{T}$-symmetric perturbation: Creation of multiple pairs of kink-antikink from phonons
• Entanglement entropy distinguishes PT-symmetry and topological phases in a class of non-unitary quantum walks
• Generic Security Analysis Framework for Quantum Secure Direct Communication