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We show that the behaviour in phase space of the Wigner function associated to the electromagnetic modes carries the information of both, the entanglement properties between matter and field, and the regions in parameter space where quantum…

Quantum Physics · Physics 2023-02-21 E. Nahmad-Achar , R. López-Peña , S. Cordero , O. Castaños

Quantum engineering now allows to design and construct multi-qubit states in a range of physical systems. These states are typically quite complex in nature, with disparate, but relevant properties that include both single and multi-qubit…

We implement a protocol to determine the degree of entanglement between a qubit and the rest of the system on a quantum computer. The protocol is based on results obtained in paper [Frydryszak et al. (2017)]. This protocol is tested on a…

Quantum Physics · Physics 2020-06-24 A. R. Kuzmak , V. M. Tkachuk

We show that real polarization method can be effectively used to geometrically quantize physical systems with compact phase space, like the spin. Our method enables us to construct a wave function of a qubit in both position and momentum…

Mathematical Physics · Physics 2015-12-10 Jerzy Kijowski , Piotr Waluk , Katarzyna Senger

We calculate the Wigner (quasi)probability distribution function of the quantum optical elliptical vortex (QEV), generated by coupling squeezed vacuum states of two modes. The coupling between the two modes is performed by using beam…

Quantum Physics · Physics 2011-04-04 Abir Bandyopadhyay , Shashi Prabhakar , R. P. Singh

Measuring the quantumness of a system can be done with a variety of methods. In this article we compare different criteria, namely quantum discord, Bell inequality violation and non-separability, for systems placed in a Gaussian state. When…

Quantum Physics · Physics 2023-04-19 Jerome Martin , Amaury Micheli , Vincent Vennin

We estimate the quantum state of a light beam from results of quantum homodyne measurements performed on identically prepared pulses. The state is represented through the Wigner function, a ``quasi-probability density'' on $\mathbb{R}^{2}$…

Statistics Theory · Mathematics 2011-06-23 Madalin Guta , Luis Artiles

The original Wigner function provides a way of representing in phase space the quantum states of systems with continuous degrees of freedom. Wigner functions have also been developed for discrete quantum systems, one popular version being…

Quantum Physics · Physics 2009-11-10 Kathleen S. Gibbons , Matthew J. Hoffman , William K. Wootters

Wigner-positive quantum states have the peculiarity to admit a Wigner function that is a genuine probability distribution over phase space. The Shannon differential entropy of the Wigner function of such states -- called Wigner entropy for…

Quantum Physics · Physics 2026-01-27 Zacharie Van Herstraeten , Nicolas J. Cerf

The Gibbs canonical state, as a maximum entropy density matrix, represents a quantum system in equilibrium with a thermostat. This state plays an essential role in thermodynamics and serves as the initial condition for nonequilibrium…

Quantum Physics · Physics 2016-06-22 Denys I. Bondar , Andre G. Campos , Renan Cabrera , Herschel A. Rabitz

The Wigner quasiprobability distribution of a narrowband single-photon state was reconstructed by quantum state tomography using photon-number-resolving measurements with transition-edge sensors (TES) at system efficiency 58(2)%. This…

Wigner functions provide a way to do quantum physics using quasiprobabilities, that is, "probability" distributions that can go negative. Informationally complete POVMs, a much younger subject than phase space formulations of quantum…

Quantum Physics · Physics 2020-10-07 John B. DeBrota , Blake C. Stacey

Quantum entanglement is a fundamental property of coherent quantum states and an essential resource for quantum computing. While two-qubit entanglement has been demonstrated for spins in silicon, creation of multipartite entanglement, a…

Mesoscale and Nanoscale Physics · Physics 2021-06-17 Kenta Takeda , Akito Noiri , Takashi Nakajima , Jun Yoneda , Takashi Kobayashi , Seigo Tarucha

The negativity of a given state's Wigner function has been proposed as a measure of quantumness of that state in a unipartite system. This otherwise physically intuitive and useful phase-space measure however does not yield the right…

Quantum Physics · Physics 2008-11-19 Tyler E Keating , Adam T. C. Steege , Arjendu K. Pattanayak

We propose the Wigner separability entropy as a measure of complexity of a quantum state. This quantity measures the number of terms that effectively contribute to the Schmidt decomposition of the Wigner function with respect to a chosen…

Quantum Physics · Physics 2012-05-23 Giuliano Benenti , Gabriel G. Carlo , Tomaz Prosen

The phase space representation for a q-deformed model of the quantum harmonic oscillator is constructed. We have found explicit expressions for both the Wigner and Husimi distribution functions for the stationary states of the…

Mathematical Physics · Physics 2007-05-23 E. I. Jafarov , S. Lievens , S. M. Nagiyev , J. Van der Jeugt

The quantum state of a light beam can be represented as an infinite dimensional density matrix or equivalently as a density on the plane called the Wigner function. We describe quantum tomography as an inverse statistical problem in which…

Statistics Theory · Mathematics 2007-06-13 L. M. Artiles , R. D. Gill , M. I. Guta

A phase space formulation of the filtering process upon an incident quantum state is developed. This formulation can explain the results of both quantum interference and delayed-choice experiments without making use of the controversial…

Quantum Physics · Physics 2009-11-10 Daniela Dragoman

Wigner's quasi-probability distribution function in phase-space is a special (Weyl) representation of the density matrix. It has been useful in describing quantum transport in quantum optics; nuclear physics; decoherence (eg, quantum…

High Energy Physics - Theory · Physics 2008-11-26 Cosmas K Zachos

We propose a method for measuring entangled vibronic quantum states of a trapped atom. It is based on the nonlinear dynamics of the system that appears by resonantly driving a weak electronic transition. The proposed technique allows the…

Quantum Physics · Physics 2009-10-30 S. Wallentowitz , R. L. de Matos Filho , W. Vogel