English
Related papers

Related papers: Quantum state discrimination in a PT-symmetric sys…

200 papers

The discrimination of non-orthogonal quantum states with reduced or without errors is a fundamental task in quantum measurement theory. In this work, we investigate a quantum measurement strategy capable of discriminating two coherent…

Quantum Physics · Physics 2010-10-12 Christoffer Wittmann , Ulrik L. Andersen , Gerd Leuchs

One of the postulates of quantum mechanics is that the Hamiltonian is Hermitian, as this guarantees that the eigenvalues are real. Recently there has been an interest in asking if $H^\dagger = H$ is a necessary condition, and has lead to…

Quantum Physics · Physics 2007-05-23 Damien Martin

Non-Hermitian physics has emerged as a rapidly advancing field of research, revealing a range of novel phenomena and potential applications. Traditional non-Hermitian Hamiltonians are typically simulated by constructing asymmetric couplings…

Quantum Physics · Physics 2026-01-26 Huawei Zhao , Xinlei Liu , Xinyao Huang , Guofeng Zhang

We report an unusual buildup of the quantum coherence in a qubit subjected to non-Hermitian evolution generated by a Parity-Time ($\mathcal{PT}$) symmetric Hamiltonian, which is reinterpreted as a Hermitian system in a higher dimensional…

Quantum Physics · Physics 2021-06-14 Javid Naikoo , Swati Kumari , A. K. Pan , Subhashish Banerjee

Quantum communication over long distances is integral to information security and has been demonstrated in free space and fibre with two-dimensional polarisation states of light. Although increased bit rates can be achieved using…

The explorations of the quantum-inspired symmetries in optical and photonic systems have witnessed immense research interests both fundamentally and technologically in a wide range of subjects of physics and engineering. One of the…

Over the past decade classical optical systems with gain or loss, modelled by non-Hermitian parity-time symmetric Hamiltonians, have been deeply investigated. Yet, their applicability to the quantum domain with number-resolved photonic…

Quantum Physics · Physics 2024-05-15 Ross Wakefield , Anthony Laing , Yogesh N. Joglekar

The optomechanical state transfer protocol provides effective, lossy, quantum beam-splitter-like dynamics where the strength of the coupling between the electromagnetic and mechanical modes is controlled by the optical steady-state…

We provide a new perspective on non-Hermitian evolution in quantum mechanics by emphasizing the same method as in the Hermitian quantum evolution. We first give a precise description of the non unitary evolution, and collecting the basic…

Quantum Physics · Physics 2017-07-21 Mustapha Maamache

Scaling beyond individual quantum devices via distributed quantum computing relies critically on high-fidelity quantum state transfers between devices, yet the quantum interconnects needed for this are currently unavailable or expected to…

Quantum Physics · Physics 2025-07-03 Marvin Bechtold , Johanna Barzen , Frank Leymann , Alexander Mandl

We investigate the evolution of open quantum systems in the presence of initial correlations with an environment. Here the standard formalism of describing evolution by completely positive trace preserving (CPTP) quantum operations can fail…

Quantum Physics · Physics 2016-09-08 Christopher J. Wood

Quantum state discrimination plays a central role in quantum information and communication. For the discrimination of optical quantum states, the two most widely adopted measurement techniques are photon detection, which produces discrete…

Quantum Physics · Physics 2026-03-11 James Moran , Spiros Kechrimparis , Hyukjoon Kwon

We have constructed a non-Hermitian two-level system (a PT -symmetric system) in dissipative environments, and investigated the quantum coherence in the non-Hermitian two-level system. Our results show that, quantum coherence can be created…

Quantum Physics · Physics 2016-12-28 Wei-Chen Wang , Mao-Fa Fang

Deterministic discrimination of nonorthogonal states is forbidden by quantum measurement theory. However, if we do not want to succeed all the time, i.e. allow for inconclusive outcomes to occur, then unambiguous discrimination becomes…

Quantum Physics · Physics 2009-11-11 Janos Bergou , Ulrike Herzog , Mark Hillery

We study the pairwise quantum discord (QD) for a symmetric multi-qubit system in different types of noisy channels, such as phase-flip, amplitude damping, phase-damping, and depolarizing channels. Using the QD and geometric measure of…

Quantum Physics · Physics 2016-02-17 You-neng Guo , Mao-fa Fang , Zeng Ke , Guo-you Wang

Open quantum systems are susceptible to losses in information, energy, and particles due to their surrounding environment. One novel strategy to mitigate these losses is to transform them into advantages for quantum technologies through…

Quantum Physics · Physics 2025-02-10 Chimdessa Gashu Feyisa , J. S. You , Huan-Yu Ku , H. H. Jen

Parity-time ($\mathcal{PT}$) symmetry plays an important role both in non-Hermitian and topological systems. In non-Hermitian systems $\mathcal{PT}$ symmetry can lead to an entirely real energy spectrum, while in topological systems…

Mesoscale and Nanoscale Physics · Physics 2019-12-18 W. B. Rui , Moritz M. Hirschmann , Andreas P. Schnyder

The quantum state discrimination problem is to distinguish between non-orthogonal quantum states. This problem has many applications in quantum information theory, quantum communication and quantum cryptography. In this paper a quantum…

Quantum Physics · Physics 2021-02-25 Doha A. Rizk , Ahmed Younes

Understanding the interplay between quantum coherence and non-Hermitian features would enable the devising of quantum technologies based on dissipative systems. In turn, quantum coherence can be characterized in terms of the language of…

Quantum Physics · Physics 2021-10-27 Diego Paiva Pires , Tommaso Macrì

The general conditions for the orthogonal product states of the multi-state systems to be used in quantum key distribution (QKD) are proposed, and a novel QKD scheme with orthogonal product states in the 3x3 Hilbert space is presented. We…

Quantum Physics · Physics 2009-11-07 Guo-Ping Guo , Chuan-Feng Li , Bao-Sen Shi , Jian Li , Guang-Can Guo