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Related papers: Gaussian quantum Markov semigroups on finitely man…

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We characterize the dynamical behavior of continuous-time, Markovian quantum systems with respect to a subsystem of interest. Markovian dynamics describes a wide class of open quantum systems of relevance to quantum information processing,…

Quantum Physics · Physics 2010-12-08 Francesco Ticozzi , Lorenza Viola

Different constructions for Hilbert state space for constrained systems are investigated. Properties of Gaussian states analogous to quantum mechanical Gaussian wave functions are studied. Their evolution for quadratic Hamiltonian case are…

Mathematical Physics · Physics 2008-12-31 O. Yu. Shvedov

We study the dynamics of quantum skyrmions under a magnetic field gradient using neural network quantum states. First, we obtain a quantum skyrmion lattice ground state using variational Monte Carlo with a restricted Boltzmann machine as…

Disordered Systems and Neural Networks · Physics 2024-03-14 Ashish Joshi , Robert Peters , Thore Posske

We investigate bosonic Gaussian quantum states on an infinite cubic lattice in arbitrary spatial dimensions. We derive general properties of such states as ground states of quadratic Hamiltonians for both critical and non-critical cases.…

Quantum Physics · Physics 2012-01-23 Norbert Schuch , J. Ignacio Cirac , Michael M. Wolf

This paper introduces an innovative approach for representing Gaussian fermionic states, pivotal in quantum spin systems and fermionic models, within a range of alternative quantum bases. We focus on transitioning these states from the…

Quantum Physics · Physics 2024-06-24 Babak Tarighi , Reyhaneh Khasseh , M. A. Rajabpour

We derive an approximate Gaussian solution of the Lindblad equation in the semiclassical limit, given a general Hamiltonian and linear coupling with the environment. The theory is carried out in the chord representation and describes the…

Quantum Physics · Physics 2009-06-24 O. Brodier , A. M. Ozorio de Almeida

We study the fidelity approach to quantum phase transitions (QPTs) and apply it to general thermal phase transitions (PTs). We analyze two particular cases: the Stoner-Hubbard itinerant electron model of magnetism and the BCS theory of…

Quantum Physics · Physics 2009-11-13 Nikola Paunkovic , Vitor Rocha Vieira

We study totally ergodic quantum dynamical systems with quasi--discrete spectrum. We investigate the classification problem for such systems in terms of algebraic invariants. The results are noncommutative analogs of (a part of) the theory…

Operator Algebras · Mathematics 2007-05-23 Slawomir Klimek

Gaussian fermionic matrix product states (GfMPS) form a class of ansatz quantum states for 1d systems of noninteracting fermions. We show, for a simple critical model of free hopping fermions, that: (i) any GfMPS approximation to its ground…

Quantum Physics · Physics 2022-12-28 Adrián Franco-Rubio , J. Ignacio Cirac

We pursue the view that quantum theory may be an emergent structure related to large space-time scales. In particular, we consider classical Hamiltonian systems in which the intrinsic proper time evolution parameter is related through a…

General Relativity and Quantum Cosmology · Physics 2014-11-17 Hans-Thomas Elze

In a recent work we presented a recursive algorithm to compute the matrix elements of a generic Gaussian transformation in the photon-number basis. Its purpose was to evolve a quantum state by building the transformation matrix and…

Quantum Physics · Physics 2021-02-12 Yuan Yao , Filippo M. Miatto

Dynamical phase transitions in the relaxation behavior of stochastic quantum walks are investigated, focusing on systems where coherent unitary evolution is periodically interrupted by dephasing. This interplay leads to a classicalization…

Quantum Physics · Physics 2025-12-01 Stefano Longhi

Characterizing the nonclassicality of quantum systems under minimal assumptions is an important challenge for quantum foundations and technology. Here we introduce a theory-independent method of process tomography and perform it on a…

Quantum Physics · Physics 2026-03-18 Albert Aloy , Matteo Fadel , Thomas D. Galley , Caroline L. Jones , Markus P. Mueller

Schwinger's algebra of selective measurements has a natural interpretation in terms of groupoids. This approach is pushed forward in this paper to show that the theory of coherent states has a natural setting in the framework of groupoids.…

Quantum Physics · Physics 2020-03-18 Fabio Di Cosmo , Alberto Ibort , Giuseppe Marmo

We study classical Hamiltonian systems in which the intrinsic proper time evolution parameter is related through a probability distribution to the physical time, which is assumed to be discrete. In this way, a physical clock with discrete…

Quantum Physics · Physics 2007-05-23 H. -T. Elze

The quantum walks in the lattice spaces are represented as unitary evolutions. We find a generator for the evolution and apply it to further understand the walks. We first extend the discrete time quantum walks to continuous time walks.…

Mathematical Physics · Physics 2013-05-09 Chul Ki Ko , Hyun Jae Yoo

We use spin-coherent states as a time-dependent variational ansatz for a semiclassical description of a large family of Heisenberg models. In addition to common approaches we also evaluate the square variance of the Hamiltonian in terms of…

Condensed Matter · Physics 2009-10-31 John Schliemann , Franz G. Mertens

Essential properties of semiclassical approximation for quantum mechanics are viewed as axioms of an abstract semiclassical mechanics. Its symmetry properties are discussed. Semiclassical systems being invariant under Lie groups are…

Mathematical Physics · Physics 2009-11-07 Oleg Yu. Shvedov

The system of N particles moving on a circle and interacting via a global repulsive cosine interaction is well known to display spatially inhomogeneous structures of extraordinary stability starting from certain low energy initial…

Statistical Mechanics · Physics 2009-11-07 F. Leyvraz , M. -C. Firpo , S. Ruffo

We present a new variational method for investigating the ground state and out of equilibrium dynamics of quantum many-body bosonic and fermionic systems. Our approach is based on constructing variational wavefunctions which extend Gaussian…

Quantum Physics · Physics 2018-03-14 Tao Shi , Eugene Demler , J. Ignacio Cirac