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Related papers: Hunting for the Quantum Cheshire Cat

200 papers

How quantum information is scrambled in the global degrees of freedom of non-equilibrium many-body systems is a key question to understand local thermalization. Here we propose that the scaling of the mutual information between two…

Statistical Mechanics · Physics 2019-10-01 Vincenzo Alba , Pasquale Calabrese

We describe two procedures which, given access to one copy of a quantum state and a sequence of two-outcome measurements, can distinguish between the case that at least one of the measurements accepts the state with high probability, and…

Quantum Physics · Physics 2017-04-18 Aram W. Harrow , Cedric Yen-Yu Lin , Ashley Montanaro

We summarize a recently proposed resolution of the quantum measurement problem. It stems from an insight into entanglement demonstrated in a 1991 experiment involving photon momenta. This experiment shows that, when two superposed quantum…

Quantum Physics · Physics 2025-06-24 Art Hobson

This article is based on a series of lectures given at ELAF 93 on the description of low-energy hadronic systems {\it in and out} of hadronic medium. The focus is put on identifying, with the help of a Cheshire Cat philosophy, the effective…

High Energy Physics - Phenomenology · Physics 2015-08-25 Mannque Rho

The measurement of a spin-$\half$ is modeled by coupling it to an apparatus, that consists of an Ising magnetic dot coupled to a phonon bath. Features of quantum measurements are derived from the dynamical solution of the measurement,…

Quantum Physics · Physics 2017-08-23 Armen E. Allahverdyan , Roger Balian , Theo M. Nieuwenhuizen

The entangled "Schrodinger's cat state" of a quantum and its measurement apparatus is not a paradoxical superposition of states but is instead a non-paradoxical superposition of nonlocal coherent correlations between states: An un-decayed…

Quantum Physics · Physics 2022-06-14 Art Hobson

An interferometric experiment is described that characterizes an optical cat state in a cavity mode. Our method describes how to measure the amplitude and phase of the different coherent states that make up the cat states. We show that…

Quantum Physics · Physics 2017-06-30 Marvellous Onuma-Kalu , Kae Nemoto , W. J. Munro , Robert B. Mann

The Horodecki criterion provides a necessary and sufficient condition for a two-qubit state to be able to manifest Bell nonlocality via violation of the Clauser-Horne-Shimony-Holt (CHSH) inequality. It requires, however, the assumption that…

Quantum Physics · Physics 2022-01-10 Michael J. W. Hall , Shuming Cheng

In quantum information theory, the reliable and effective detection of entanglement is of paramount importance. However, given an unknown state, assessing its entanglement is a challenging task. To attack this problem, we investigate the…

Quantum Physics · Physics 2015-12-09 Jochen Szangolies , Hermann Kampermann , Dagmar Bruß

Photon indistinguishability is an essential concept to understanding mysterious quantum features from the viewpoint of the wave-particle duality in quantum mechanics. The physics of indistinguishability lies in the manipulation of quantum…

Quantum Physics · Physics 2023-08-15 B. S. Ham

We are concerned with the justification of the statement, commonly (explicitly or implicitly) used in quantum scattering theory, that for a free non-relativistic quantum particle with initial wave function $\Psi_0(\boldsymbol{x})$,…

Quantum Physics · Physics 2026-02-13 Rashi Kaimal , Roderich Tumulka

We propose a novel quantum technique to search for unmodeled anomalies in multidimensional binned collider data. We propose associating an Ising lattice spin site with each bin, with the Ising Hamiltonian suitably constructed from the…

High Energy Physics - Phenomenology · Physics 2025-06-30 Konstantin T. Matchev , Prasanth Shyamsundar , Jordan Smolinsky

We theoretically derive the probability densities of the entanglement measures of a pure non-ergodic many-body state, represented in a bipartite product basis and with its reduced density matrix described by a generalized, multi-parametric…

Quantum Physics · Physics 2024-12-11 Devanshu Shekhar , Pragya Shukla

Certain quantum states are well-known to be particularly fragile in the presence of decoherence, as illustrated by Schrodinger's famous gedanken cat experiment. It has been better appreciated more recently that quantum states can be…

We provide quantitative bounds on the characterisation of multiparticle separable states by states that have locally symmetric extensions. The bounds are derived from two-particle bounds and relate to recent studies on quantum versions of…

Quantum Physics · Physics 2012-10-22 Fernando G. S. L. Brandao , Matthias Christandl

We consider symmetric hypothesis testing in quantum statistics, where the hypotheses are density operators on a finite-dimensional complex Hilbert space, representing states of a finite quantum system. We prove a lower bound on the…

Quantum Physics · Physics 2009-04-30 Michael Nussbaum , Arleta Szkoła

We investigate the utility of non classical states of simple harmonic oscillators (a superposition of coherent states) for sensitive force detection. We find that like squeezed states a superposition of coherent states allows the detection…

Quantum Physics · Physics 2007-05-23 Kae Nemoto , W. J. Munro , G. J. Milburn , S. L. Braunstein

We investigate disordered one- and two-dimensional Heisenberg spin lattices across a transition from integrability to quantum chaos from both a statistical many-body and a quantum-information perspective. Special emphasis is devoted to…

Quantum Physics · Physics 2009-11-13 Winton G. Brown , Lea F. Santos , David J. Starling , Lorenza Viola

From the ancient Einstein-Podolsky-Rosen paradox to the recent Sorkin-type impossible measurements problem, the contradictions between relativistic causality, quantum non-locality, and quantum measurement have persisted. Based on quantum…

Quantum Physics · Physics 2025-10-03 Kaixun Tu , Qing Wang

Separability problem is a long-standing tough issue in quantum information theory. In this paper, we propose a general method to detect entanglement via arbitrary measurement $\boldsymbol{X}$, by which several novel criteria are…

Quantum Physics · Physics 2022-08-18 Ma-Cheng Yang , Cong-Feng Qiao