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arXiv:2511.09990 · Annals of Physics

Improved coherence time of a non-Hermitian qubit in a $\mathcal{PT}$-symmetric Environment

Duttatreya, Ipsika Mohanty, Sanjib Dey

quant-phmath-phSubmitted Nov 13, 2025• Announced Nov 14, 2025• 2 citations
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Abstract

Quantum computing's potential for exponential speedup is fundamentally limited by decoherence, a phenomenon arising from environmental interactions. Non-Hermitian quantum mechanics, particularly $PT$-symmetric systems, offers a novel framework for extending coherence times. This study examines a qubit's coherence under non-Hermitian $PT$-symmetric dynamics, highlighting significantly enhanced coherence times compared to Hermitian setups. The effect is especially pronounced when both the system and environment exhibit $PT$-symmetry. Interestingly, greater environmental non-Hermiticity correlates with extended coherence, contrary to traditional expectations. These findings point to promising strategies for managing decoherence, which could significantly advance approaches to quantum information processing.

Journal reference
Annals of Physics 484, 170298 (2025)
DOI
10.1016/j.aop.2025.170298
Comments
9 pages, 6 figures

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This paper explores the potential of leveraging quantum decoherence for hardware acceleration in quantum computation. The core claim is that by strategically manipulating environmental noise, we can enhance both the accuracy and efficiency of simulating quantum systems. The proposed mechanism centers on suppressing qubit-qubit interactions through controlled noise, thereby extending coherence times and ultimately improving computational outcomes. This represents a novel approach to quantum computation, directly utilizing the inherent properties of quantum decoherence to achieve computational speedups. We detail theoretical frameworks and explore potential strategies, focusing on the fundamental relationship between decoherence and computational fidelity. The work emphasizes the design principles for quantum systems engineered to maximize the beneficial effects of decoherence while minimizing detrimental impacts. This approach offers a promising route towards more practical and scalable quantum simulations.