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Related papers: Comment on the Quantum Brachistochrone Problem

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The author discusses a different kind of Hermitian quantum mechanics, called $J$-Hermitian quantum mechanics. He shows that $PT$-symmetric quantum mechanics is indeed $J$-Hermitian quantum mechanics, and that time evolution (in the Krein…

Quantum Physics · Physics 2014-01-22 Sungwook Lee

We report on a time scaling technique to enhance the performances of quantum protocols in non-Hermitian systems. The considered time scaling involves no extra-couplings and yields a significant enhancement of the quantum fidelity for a…

Quantum Physics · Physics 2021-12-08 F. Impens , F. M. D'Angelis , F. A. Pinheiro , D. Guéry-Odelin

In this paper, we derive sharp lower bounds, also known as quantum speed limits, for the time it takes to transform a quantum system into a state such that an observable assumes its lowest average value. We assume that the system is…

Quantum Physics · Physics 2021-06-02 Dan Allan , Niklas Hörnedal , Ole Andersson

Phenomenological studies of quantum gravity have proposed a modification of the commutator between position and momentum in quantum mechanics so to introduce a minimal uncertainty in position in quantum mechanics. Such a minimal uncertainty…

General Relativity and Quantum Cosmology · Physics 2023-02-10 Pasquale Bosso

We consider a non-Hermitian Hamiltonian in order to effectively describe a two-level system coupled to a generic dissipative environment. The total Hamiltonian of the model is obtained by adding a general anti-Hermitian part, depending on…

Quantum Physics · Physics 2013-10-25 Alessandro Sergi , Konstantin G. Zloshchastiev

In this paper a quantum mechanics is built by means of a non-Hermitian momentum operator. We have shown that it is possible to construct two Hermitian and two non-Hermitian type of Hamiltonians using this momentum operator. We can construct…

Mathematical Physics · Physics 2011-03-25 Juan M. Romero , O. Gonzalez-Gaxiola , J. Ruiz de Chavez , R. Bernal-Jaquez

We define a new quantum Hermitian operator (namely, the energy variance operator) which is simply duplicated from the statistical definition of energy variance in classical physics. Its expectation value yields the standard deviation of the…

Quantum Physics · Physics 2022-05-26 Gilbert Reinisch

We explore the consequences of allowing non-Hermitian structures in quantum cosmology by extending the Wheeler DeWitt framework beyond strictly Hermitian dynamics. Using a controlled semiclassical reduction, we show how anti Hermitian…

Cosmology and Nongalactic Astrophysics · Physics 2026-02-06 Oem Trivedi , Alfredo Gurrola

Both conservation laws and practical restrictions impose symmetry constraints on the dynamics of open quantum systems. In the case of time-translation symmetry, which arises naturally in many physically relevant scenarios, the quantum…

Quantum Physics · Physics 2017-09-14 Matteo Lostaglio , Kamil Korzekwa , Antony Milne

We discuss the short-time perturbative expansion of the linear entropy for finite-dimensional quantum systems whose dynamics can be effectively described by a non-Hermitian Hamiltonian. We derive a timescale for the degree of mixedness for…

Quantum Physics · Physics 2023-02-07 Diego Paiva Pires , Tommaso Macrì

Non hermitian Hamiltonians play an important role in the study of dissipative quantum systems. We show that using states with time dependent normalization can simplify the description of such systems especially in the context of the…

Quantum Physics · Physics 2016-02-09 Kushagra Nigam , Kinjal Banerjee

Hamiltonian mechanics describes the evolution of a system through its Hamiltonian. The Hamiltonian typically also represents the energy observable, a Noether-conserved quantity associated with the time-invariance of the law of evolution. In…

Quantum Physics · Physics 2024-03-29 Libo Jiang , Daniel R. Terno , Oscar Dahlsten

Efficient control of qubits plays a key role in quantum information processing. In the current work, an alternative set of differential equations are derived for an optimal quantum control of single or multiple qubits with or without…

Quantum Physics · Physics 2020-11-26 Ding Wang , Haowei Shi , Yueheng Lan

The phenomenon of quantum phase transition is considered in the special case in which the evolution laws remain unitary and in which the bound-state energies remain observable. The conventional Hermiticity of observables is lost at the…

Quantum Physics · Physics 2018-04-24 Miloslav Znojil

To find and realize the optimal evolution between two states is significant both in theory and application. In quantum mechanics, the minimal evolution is bounded by the gap between the largest and smallest eigenvalue of the Hamiltonian. In…

Quantum Physics · Physics 2013-04-29 Chao Zheng , Liang Hao , Gui Lu Long

In the study of bi-Hamiltonian systems (both classical and quantum) one starts with a given dynamics and looks for all alternative Hamiltonian descriptions it admits.In this paper we start with two compatible Hermitian structures (the…

Quantum Physics · Physics 2009-11-07 G. Marmo , G. Morandi , A. Simoni , F. Ventriglia

To overcome the fast oscillatory behavior of correlation functions for extracting scattering phase shift in real-time quantum simulations encountered in Ref.\cite{Guo:2026qkx}, we propose and test two solutions in the present work. One is…

Quantum Physics · Physics 2026-04-02 Peng Guo , Paul LeVan , Frank X. Lee , Yong Zhao

The speed limit of quantum state transfer (QST) in a system of interacting particles is not only important for quantum information processing, but also directly linked to Lieb-Robinson-type bounds that are crucial for understanding various…

Quantum Physics · Physics 2023-11-28 Casey Jameson , Bora Basyildiz , Daniel Moore , Kyle Clark , Zhexuan Gong

Despite acute interest in the dynamics of non-Hermitian systems, there is a lack of consensus in the mathematical formulation of non-Hermitian quantum mechanics in the community. Different methodologies are used in the literature to study…

Quantum Physics · Physics 2025-03-31 Karin Sim , Nicolò Defenu , Paolo Molignini , R. Chitra

The PT-symmetric (PTS) quantum brachistochrone problem is reanalyzed as quantum system consisting of a non-Hermitian PTS component and a purely Hermitian component simultaneously. Interpreting this specific setup as subsystem of a larger…

Quantum Physics · Physics 2008-10-31 Uwe Guenther , Boris F. Samsonov