Quantum Dynamics and Information Measures in PT and Anti-PT-Symmetric Systems

TL;DR

This paper explores the dynamics of qubits in PT and Anti-PT-symmetric systems, revealing that Anti-PT symmetry offers enhanced robustness against decoherence and better quantum information preservation.

Contribution

It introduces a detailed analysis of qubit behavior in PT and Anti-PT-symmetric Hamiltonians, highlighting the advantages of Anti-PT symmetry for quantum information stability.

Findings

Anti-PT systems show slower decoherence and entropy growth.

Anti-PT-symmetric qubits better preserve quantum information.

QSL behavior is non-monotonic, with rapid initial evolution.

Abstract

In this study, we investigate qubit dynamics under PT and Anti-PT-symmetric non-Hermitian Hamiltonians, focusing on phase evolution, decoherence, quantum speed limits (QSL), and R\'enyi entanglement entropies. Using similarity transformations and Dyson maps, we analyze the reduced density matrix evolution in bosonic environments. Anti-PT-symmetric systems show enhanced robustness against decoherence, with slower entropy growth and longer coherence times compared to PT-symmetric counterparts. QSL behavior is non-monotonic, reflecting rapid initial evolution followed by a gradual decrease. Higher-order R\'enyi entropies reveal that Anti-PT-symmetric qubits preserve quantum information more effectively, offering advantages for memory and cryptographic applications.