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Related papers: A non-Hermitian loop for a quantum measurement

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A new energy-based stochastic extension of the Schrodinger equation for which the wave function collapses after the passage of a finite amount of time is proposed. An exact closed-form solution to the dynamical equation, valid for all…

Quantum Physics · Physics 2009-11-11 Dorje C. Brody , Lane P. Hughston

We address the nonadiabatic quantum dynamics of macrosystems with several coupled electronic states, taking into account the possibility of multi-state conical intersections. The general situation of an arbitrary number of states and…

Chemical Physics · Physics 2009-11-13 Etienne Gindensperger , Lorenz S. Cederbaum

Non-Hermitian systems are widespread in both classical and quantum physics. The dynamics of such systems has recently become a focal point of research, showcasing surprising behaviors that include apparent violation of the adiabatic theorem…

Quantum Physics · Physics 2026-01-15 Parveen Kumar , Yuval Gefen , Kyrylo Snizhko

Non-Hermitian Hamiltonians enrich quantum physics by extending conventional phase diagrams, enabling novel topological phenomena, and realizing exceptional points with potential applications in quantum sensing. Here, we present an…

Evolutions under non-Hermitian Hamiltonians with unbroken $\mathcal{PT}$ symmetry can be considered unitary under appropriate choices of inner products, facilitated by the so-called metric operator. While it is understood that the choice of…

Quantum Physics · Physics 2025-12-04 Himanshu Badhani , C. M. Chandrashekar

We present two examples of non-Hermitian Hamiltonians which consist of an unperturbed part plus a perturbation that behaves like a vector, in the framework of PT quantum mechanics. The first example is a generalization of the recent work by…

Quantum Physics · Physics 2014-07-02 Katherine Jones-Smith , Rudolph Kalveks

Arguments have been raised that the system--observer cut of quantum mechanics can be shifted arbitrarily close to, or even into, the conscious observer. Here I show that this view leads to {\it observable} contradictions (despite our…

Quantum Physics · Physics 2007-05-23 Bernd A. Berg

In the conventional Schr\"{o}dinger's formulation of quantum mechanics the unitary evolution of a state $\psi$ is controlled, in Hilbert space ${\cal L}$, by a Hamiltonian $\mathfrak{h}$ which must be self-adjoint. In the recent,…

Quantum Physics · Physics 2023-12-21 Olaf Lechtenfeld , Miloslav Znojil

We present quantum algorithms for simulating the dynamics of a broad class of classical oscillator systems containing $2^n$ coupled oscillators (Eg: $2^n$ masses coupled by springs), including those with time-dependent forces, time-varying…

Quantum Physics · Physics 2025-05-26 Abhinav Muraleedharan , Nathan Wiebe

We survey some of the main conceptual developments in the study of PT-symmetric and pseudo-Hermitian Hamiltonian operators that have taken place during the past ten years or so. We offer a precise mathematical description of a quantum…

Quantum Physics · Physics 2015-05-19 Ali Mostafazadeh

The $\mathcal{PT}$-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…

Quantum Physics · Physics 2021-03-24 Jingwei Wen , Chao Zheng , Zhangdong Ye , Tao Xin , Guilu Long

A cavity quantum electrodynamical scenario is proposed for implementing a Schr\"odinger microscope capable of amplifying differences between non orthogonal atomic quantum states. The scheme involves an ensemble of identically prepared…

In quantum mechanics without application of any superselection rule to the set of the observables, a closed quantum system temporally evolves unitarily, and this Lorentzian regime is characterized by von Neumann entropy of exactly zero. In…

Quantum Physics · Physics 2023-04-03 Eiji Konishi

We discuss a model of spontaneous collapse of the quantum state that does not require adding any stochastic processes to the standard dynamics. The additional ingredient with respect to the wave function is a position in the configuration…

Quantum Physics · Physics 2019-05-28 Franck Laloë

The interaction picture in a non-Hermitian realization is discussed in detail and considered for its practical use in many-body quantum physics. The resulting non-Hermitian interaction-picture (NHIP) description of dynamics, in which both…

Quantum Physics · Physics 2020-04-29 R. F. Bishop , M. Znojil

Starting from the Schr\"odinger-equation of a composite system, we derive unified dynamics of a classical harmonic system coupled to an arbitrary quantized system. The classical subsystem is described by random phase-space coordinates…

Quantum Physics · Physics 2007-05-23 Lajos Diosi

This is a review paper concerned with the global consistency of the quantum dynamics of non-commutative systems. Our point of departure is the theory of constrained systems, since it provides a unified description of the classical and…

High Energy Physics - Theory · Physics 2015-05-13 F. S. Bemfica , H. O. Girotti

It is shown that non-Markovian master equations for an open system which are local in time can be unravelled through a piecewise deterministic quantum jump process in its Hilbert space. We derive a stochastic Schr\"odinger equation that…

Quantum Physics · Physics 2009-11-13 Heinz-Peter Breuer , Jyrki Piilo

Statistical mechanics of the discrete nonlinear Schr\"odinger equation is studied by means of analytical and numerical techniques. The lower bound of the Hamiltonian permits the construction of standard Gibbsian equilibrium measures for…

Statistical Mechanics · Physics 2009-10-31 K. Ø. Rasmussen , T. Cretegny , P. G. Kevrekidis , N. Grønbech-Jensen

In this paper, we describe some interesting properties of a non-Hermitian Jaynes-Cummings model. For this particular model, it is known that the Hilbert space can be described by infinitely-many two-dimensional invariant (closed) subspaces,…

Quantum Physics · Physics 2026-04-23 Gargi Das , Aritra Ghosh , Bhabani Prasad Mandal