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Related papers: Phase-space quantum Wiener-Khintchine theorem

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Representations of quantum state vectors by complex phase space amplitudes, complementing the description of the density operator by the Wigner function, have been defined by applying the Weyl-Wigner transform to dyadic operators, linear in…

Quantum Physics · Physics 2015-05-19 A. J. Bracken , P. Watson

Quantum coherence quantifies the amount of superposition in a quantum system, and is the reason and resource behind several phenomena and technologies. It depends on the natural basis in which the quantum state of the system is expressed,…

Quantum Physics · Physics 2021-08-13 Ingita Banerjee , Kornikar Sen , Chirag Srivastava , Ujjwal Sen

We provide an introduction into the formulation of non-relativistic quantum mechanics using the Wigner phase-space distribution function and apply this concept to two physical situations at the interface of quantum theory and general…

The article explores a new formalism for describing motion in quantum mechanics. The construction is based on generalized coherent states with evolving fiducial vector. Weyl-Heisenberg coherent states are utilised to split quantum systems…

General Relativity and Quantum Cosmology · Physics 2020-09-10 Artur Miroszewski

An extension to computational mechanics complexity measure is proposed in order to tackle quantum states complexity quantification. The method is applicable to any $n-$partite state of qudits through some simple modifications. A Werner…

Computational Physics · Physics 2011-10-28 Yuri Campbell , José Roberto Castilho Piqueira

We propose a method to identify the order of a Quantum Phase Transition by using area measures of the ground state in phase space. We illustrate our proposal by analyzing the well known example of the Quantum Cusp, and four different…

Quantum Physics · Physics 2016-10-13 O. Castaños , M. Calixto , F. Pérez-Bernal , E. Romera

Quantum theory predicts probabilities as well as relative phases between different alternatives of the system. A unified description of both probabilities and phases comes through a generalisation of the notion of a density matrix for…

Quantum Physics · Physics 2016-09-08 Charis Anastopoulos

We presented the topological current of Ehrenfest definition of phase transition. It is shown that different topology of the configuration space corresponds to different phase transition, it is marked by the Euler number of the interaction…

Statistical Mechanics · Physics 2007-05-23 Tieyan Si

The mechanism of the transition of a dynamical system from quantum to classical mechanics is one of the remaining challenges of quantum theory. Currently, it is considered to occur via decoherence caused by entanglement and/or stochastic…

Quantum Physics · Physics 2015-06-16 John S. Briggs , James M. Feagin

In the usual formulation of quantum mechanics, groups of automorphisms of quantum states have ray representations by unitary and antiunitary operators on complex Hilbert space, in accordance with Wigner's Theorem. In the phase-space…

Mathematical Physics · Physics 2017-02-23 A. J. Bracken , G. Cassinelli , J. G. Wood

A new non-perturbative approach to quantum theory in curved spacetime and to quantum gravity, based on a generalisation of the Wigner equation, is proposed. Our definition for a Wigner equation differs from what have otherwise been…

High Energy Physics - Theory · Physics 2009-10-30 Frank Antonsen

We derive the form of the quantum filter equation describing the continuous observation of the phase of a quantum system in an arm of an interferometer via non-demolition measurements when the statistics of an input field used for the…

Quantum Physics · Physics 2016-01-19 John Gough

The recently established resource theory of quantum coherence allows for a quantitative understanding of the superposition principle, with applications reaching from quantum computing to quantum biology. While different quantifiers of…

We consider symmetry as a foundational concept in quantum mechanics and rewrite quantum mechanics and measurement axioms in this description. We argue that issues related to measurements and physical reality of states can be better…

Quantum Physics · Physics 2018-04-11 Houri Ziaeepour

We apply the generalized Wigner function formalism to detect and characterize a range of quantum phase transitions in several cyclic, finite-length, spin-$\frac{1}{2}$ one-dimensional spin-chain models, viz., the Ising and anisotropic $XY$…

Quantum Physics · Physics 2023-10-03 N. M. Millen , R. P. Rundle , J. H. Samson , Todd Tilma , R. F. Bishop , M. J. Everitt

Quantum phase estimation is a core task in quantum technologies ranging from metrology to quantum computing, where it appears as a key subroutine in various algorithms. Here, we quantitatively connect the performance of phase estimation…

Quantum Physics · Physics 2026-05-11 Felix Ahnefeld , Thomas Theurer , Martin B. Plenio

Quantum coherence plays a crucial role in manipulating and controlling quantum systems, leading to breakthroughs in various fields such as quantum information, quantum sensing, and the detection of gravitational waves. Most coherence…

Quantum Physics · Physics 2024-04-16 Yan-Han Yang , Xue Yang , Xing-Zhou Zheng , Ming-Xing Luo

Quantum coherence is important in quantum mechanics, and its essence is from superposition principle. We study the coherence of any two pure states and that of their arbitrary superposition, and obtain the relationship between them. In the…

Quantum Physics · Physics 2016-05-25 Qiu-Ling Yue , Chao-Hua Yu , Feng Liu , Xiao-Li Wang , Fei Gao , Qiao-Yan Wen

We witness experimentally the presence of macroscopic coherence in Gaussian quantum states using a recently proposed criterion (E.G. Cavalcanti and M. Reid, Phys. Rev. Lett. 97, 170405 (2006)). The macroscopic coherence stems from…

The application of geometry to physics has provided us with new insightful information about many physical theories such as classical mechanics, general relativity, and quantum geometry (quantum gravity). The geometry also plays an…

Quantum Physics · Physics 2015-06-19 Hoshang Heydari