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Following an approach based on generating function method phase space characteristics of Landau system are studied in the autonomous framework of deformation quantization. Coherent state property of generating functions is established and…

Quantum Physics · Physics 2007-05-23 B. Demircioglu , A. Vercin

The observation of quantum phenomena often necessitates sufficiently pure states, a requirement that can be challenging to achieve. In this study, our goal is to prepare a non-classical state originating from a mixed state, utilizing…

Quantum Physics · Physics 2025-04-08 Ian Yang , Thomas Agrenius , Vasilisa Usova , Oriol Romero-Isart , Gerhard Kirchmair

We present a theoretical treatment of conditional preparation of one-photon states from a continuous-wave non-degenerate optical parametric oscillator. We obtain an analytical expression for the output state Wigner function, and we maximize…

Quantum Physics · Physics 2014-10-09 Anne E. B. Nielsen , Klaus Mølmer

We propose an entanglement criterion, specially designed for mixed states, based on uncertainty relation and the Wigner-Yanase skew information. The variances in this uncertainty relation does not involve any classical mixing uncertainty,…

Quantum Physics · Physics 2022-11-01 Manju Maan , Asoka Biswas , Shubhrangshu Dasgupta

We introduce a new non-Gaussian state, generated by m times coherent superposition operation $a\cos \theta +a^{\dagger }e^{i\varphi }\sin \theta $ (MCSO) on odd-Schrodinger-cat state (OSCS). Its normalized constant is turned out to be…

Quantum Physics · Physics 2015-06-22 Li Huang , Qin Guo , Li-ying Jiang , Ge Chen , Xue-xiang Xu , Wen Yuan

We propose a new test of local realism based on correlation measurements of continuum valued functions of positions and momenta, known as modular variables. The Wigner representation of these observables are bounded in phase space, and…

Quantum Physics · Physics 2015-12-10 Atul S. Arora , Ali Asadian

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

This dissertation serves as a general introduction to Wigner functions, phase space, and quantum metrology but also strives to be useful as a how-to guide for those who wish to delve into the realm of using continuous variables, to describe…

Quantum Physics · Physics 2016-05-05 Bryan Gard

Negativity in a quasiprobability representation is typically interpreted as an indication of nonclassical behavior. However, this does not preclude states that are non-negative from exhibiting phenomena typically associated with quantum…

Quantum Physics · Physics 2012-08-23 Joel J. Wallman , Stephen D. Bartlett

Positive definite functions are very important in both theory and applications of approximation theory, probability and statistics. In particular, identifying strictly positive definite kernels is of great interest as interpolation problems…

Classical Analysis and ODEs · Mathematics 2011-10-12 R. K. Beatson , W. zu Castell , Y. Xu

Quantum correlation provides a promising measure beyond entanglement. Here, we propose a necessary and sufficient condition for nonzero quantum correlation in continuous variable systems, which is simple and easy to perform in terms of a…

Quantum Physics · Physics 2015-11-12 Chengjie Zhang , Sixia Yu , Qing Chen , Haidong Yuan , C. H. Lai , C. H. Oh

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 obtain a necessary and sufficient condition for a finite set of states of a finite dimensional multiparticle quantum system to be amenable to unambiguous discrimination using local operations and classical communication. This condition…

Quantum Physics · Physics 2009-11-10 Anthony Chefles

Optical cat state plays an essential role in quantum computation and quantum metrology. Here, we experimentally quantify quantum coherence of an optical cat state by means of relative entropy and l_1 norm of coherence in Fock basis based on…

Quantum Physics · Physics 2021-05-07 Miao Zhang , Haijun Kang , Meihong Wang , Fengyi Xu , Xiaolong Su , Kunchi Peng

The Wigner function of a finite-dimensional system can be constructed via dual pairing of a density matrix with the Stratonovich-Weyl kernel. Following Kenfack and $\dot{\text{Z}}$yczkowski, we consider the indicator of nonclassicality of a…

Quantum Physics · Physics 2021-12-30 Vahagn Abgaryan , Arsen Khvedelidze , Astghik Torosyan

The quantum state of Schroedinger's cat is usually incorrectly described as a superposition of "dead" and "alive," despite an argument by Rinner and Werner that, locally, the cat should be considered to be in a mixture of non-superposed…

Quantum Physics · Physics 2022-06-14 Art Hobson

We argue that all consistent 4D quantum field theories obey a spacetime-averaged weak energy inequality $\langle T^{00} \rangle \ge -C/L^4$, where $L$ is the size of the smearing region, and $C$ is a positive constant that depends on the…

High Energy Physics - Theory · Physics 2016-11-03 Kara Farnsworth , Markus A. Luty , Valentina Prilepina

The Wigner function $W_N({\bf x}, {\bf p})$ is a useful quantity to characterize the quantum fluctuations of an $N$-body system in its phase space. Here we study $W_N({\bf x}, {\bf p})$ for $N$ noninteracting spinless fermions in a…

Statistical Mechanics · Physics 2021-07-28 Benjamin De Bruyne , David S. Dean , Pierre Le Doussal , Satya N. Majumdar , Gregory Schehr

In recent papers [1,2], it has been shown that the presence of negative norm states or negative frequency solutions are indispensable for a fully covariant quantization of the minimally coupled scalar field in de Sitter space. Their…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Mohammad Vahid Takook

We present a scheme to deterministically prepare non-classical quantum states of a massive mirror including highly non-Gaussian states exhibiting sizeable negativity of the Wigner function. This is achieved by exploiting the non-linear…

Quantum Physics · Physics 2018-09-20 Ludovico Latmiral , Florian Mintert