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Related papers: A new Phase Space Density for Quantum Expectations

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Non-classical states are of practical interest in quantum computing and quantum metrology. These states can be detected through their Wigner function negativity in some regions. In this paper, we calculate the ground state of the…

Quantum Physics · Physics 2021-02-03 Ramón López-Peña , Sergio Cordero , Eduardo Nahmad-Achar , Octavio Castaños

The Wigner-Weyl transform and phase space formulation of a density matrix approach are applied to a non-Hermitian model which is quadratic in positions and momenta. We show that in the presence of a quantum environment or reservoir, mean…

Quantum Physics · Physics 2019-10-09 Ludmila Praxmeyer , Konstantin G. Zloshchastiev

The standard model of classical Density Functional Theory for pair potentials consists of a hard-sphere functional plus a mean-field term accounting for long ranged attraction. However, most implementations using sophisticated Fundamental…

Computational Physics · Physics 2021-01-04 James F. Lutsko , Cédric Schoonen

We propose a phase-space representation concept in terms of the Wigner function for a quantum harmonic oscillator model that exhibits the semiconfinement effect through its mass varying with the position. The new method is used to compute…

Quantum Physics · Physics 2024-02-01 S. M. Nagiyev , A. M. Jafarova , E. I. Jafarov

Discrete quantum phase space formalism is used to discuss some basic aspects of the spin tunneling occurring in Fe8 magnetic cluster by means of Wigner functions as well as Husimi distributions. Those functions were obtained for sharp angle…

Quantum Physics · Physics 2008-11-15 Evandro C. Silva , Diogenes Galetti

We propose a new generalised formalism for estimating the quantum phase uncertainty of pure and mixed continuous-variable quantum states and compare this with the phase uncertainty given by the quantum Fisher information. In order to…

Quantum Physics · Physics 2014-04-02 Jaewoo Joo , Jacob A. Dunningham , Daniel K. L. Oi , Timothy P. Spiller

We derive entropic inseparability criteria for the phase space representation of quantum states. In contrast to criteria involving differential entropies of marginal phase space distributions, our criteria are based on a joint distribution…

Quantum Physics · Physics 2022-01-10 Stefan Floerchinger , Martin Gärttner , Tobias Haas , Oliver R. Stockdale

Quantum devices are preparing increasingly more complex entangled quantum states. How can one effectively study these states in light of their increasing dimensions? Phase spaces such as Wigner functions provide a suitable framework. We…

Quantum Physics · Physics 2021-01-04 Bálint Koczor , Robert Zeier , Steffen J. Glaser

We introduce a positive phase-space representation for fermions, using the most general possible multi-mode Gaussian operator basis. The representation generalizes previous bosonic quantum phase-space methods to Fermi systems. We derive…

Other Condensed Matter · Physics 2009-11-10 J. F. Corney , P. D. Drummond

We develop a semiclassical density functional theory in the context of quantum dots. Coulomb blockade conductance oscillations have been measured in several experiments using nanostructured quantum dots. The statistical properties of these…

Mesoscale and Nanoscale Physics · Physics 2009-10-31 Denis Ullmo , Tatsuro Nagano , Steven Tomsovic , Harold U. Baranger

The density operator for a quantum system in thermal equilibrium with its environment depends on Planck's constant, as well as the temperature. At high temperatures, the Weyl representation, that is, the thermal Wigner function, becomes…

Quantum Physics · Physics 2021-06-30 Alfredo M. Ozorio de Almeida , Gert-Ludwig Ingold , Olivier Brodier

Within the quantum phase representation we derive Heisenberg limits, in closed form, for N00N states and two other classes of states that can perform better in terms of local performance metrics relevant for multiply-peaked distributions.…

Quantum Physics · Physics 2016-03-09 Scott Roger Shepard , Frederick Ira Moxley , Jonathan P. Dowling

General semiclassical expression for quantum fidelity (Loschmidt echo) of arbitrary pure and mixed states is derived. It expresses fidelity as an interference sum of dephasing trajectories weighed by the Wigner function of the initial…

Quantum Physics · Physics 2007-05-23 Jiri Vanicek

We introduce quantum hypercube states, a class of continuous-variable quantum states that are generated as orthographic projections of hypercubes onto the quadrature phase-space of a bosonic mode. In addition to their interesting geometry,…

Quantum Physics · Physics 2019-07-24 L. A. Howard , T. J. Weinhold , F. Shahandeh , J. Combes , M. R. Vanner , A. G. White , M. Ringbauer

We propose to study the $L^2$-norm distance between classical and quantum phase space distributions, where for the latter we choose the Wigner function, as a global phase space indicator of quantum-classical correspondence. For example,…

Quantum Physics · Physics 2009-11-13 Martin Horvat , Tomaz Prosen , Mirko Degli Esposti

We formulate, with full generality, the asymptotic estimation theory for Gaussian states in terms of their first and second moments. By expressing the quantum Fisher information (QFI) and the elusive symmetric logarithmic derivative (SLD)…

Quantum Physics · Physics 2013-03-18 Alex Monras

We discuss thermalization of isolated quantum systems by using the Husimi-Wehrl entropy evaluated in the semiclassical treatment. The Husimi-Wehrl entropy is the Wehrl entropy obtained by using the Husimi function for the phase space…

High Energy Physics - Phenomenology · Physics 2015-12-29 Hidekazu Tsukiji , Hideaki Iida , Teiji Kunihiro , Akira Ohnishi , Toru T. Takahashi

The new scheme employed (throughout the thermodynamic phase space), in the statistical thermodynamic investigation of classical systems, is extended to quantum systems. Quantum Nearest Neighbor Probability Density Functions are formulated…

Statistical Mechanics · Physics 2015-06-25 U. F. Edgal , D. L. Huber

In this paper, a new representation of the Wigner function for a quantum system in the phase space is proposed. The new representation is of the form $W=\operatorname{Sp}\left[ \rho \mathcal{W} \right]$, where $\rho$ is the density matrix,…

Mathematical Physics · Physics 2019-04-11 E. E. Perepelkin , B. I. Sadovnikov , N. G. Inozemtseva , E. V. Burlakov

The quantum evolution of the Wigner function for Gaussian wave packets generated by a non-Hermitian Hamiltonian is investigated. In the semiclassical limit $\hbar\to 0$ this yields the non-Hermitian analog of the Ehrenfest theorem for the…

Quantum Physics · Physics 2011-07-04 Eva-Maria Graefe , Roman Schubert
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