English
Related papers

Related papers: A geometric measure of non-classicality

200 papers

The probability density distributions for the ground states of certain model systems in quantum mechanics and for their classical counterparts are considered. It is shown, that classical distributions are remarkably improved by…

Quantum Physics · Physics 2025-01-23 Tomasz Radozycki

Quantum polarization is investigated by means of a trajectory picture based on the Bohmian formulation of quantum mechanics. Relevant examples of classical-like two-mode field states are thus examined, namely Glauber and SU(2) coherent…

Quantum Physics · Physics 2015-09-02 Alfredo Luis , Angel S. Sanz

Coherent or semiclassical states in canonical quantum gravity describe the classical Schwarzschild space-time. By tracing over the coherent state wavefunction inside the horizon, a density matrix is derived. Bekenstein-Hawking entropy is…

General Relativity and Quantum Cosmology · Physics 2009-11-11 Arundhati Dasgupta

A new measure of non-classical correlations is introduced and characterized. It tests the ability of using a state {\rho} of a composite system AB as a probe for a quantum illumination task [e.g. see S. Lloyd, Science 321, 1463 (2008)], in…

Quantum Physics · Physics 2014-07-17 A. Farace , A. De Pasquale , L. Rigovacca , V. Giovannetti

Non-Gaussian and nonclassical states and processes are already found to be important resources for performing various tasks related to quantum gravity and quantum information processing. The effect of non-Gaussianity inducing operators on…

Quantum Physics · Physics 2021-09-28 Priya Malpani , Kishore Thapliyal , J. Banerji , Anirban Pathak

We consider the nonclassicality distance indicator of a state in finite-dimensional quantum systems which is evaluating a state nonclassicality by its remoteness from the set of "classical states". The latter are identified with those…

Quantum Physics · Physics 2023-10-20 Arsen Khvedelidze , Astghik Torosyan

In this work we generalize the Bochner criterion addressing the characteristic function, i.e., the Fourier transform, of the Glauber-Sudarshan phase-space function. For this purpose we extend the Bochner theorem by including derivatives of…

Quantum Physics · Physics 2015-07-29 Sergej Ryl , Jan Sperling , Elizabeth Agudelo , Melanie Mraz , Semjon Köhnke , Boris Hage , Werner Vogel

We introduce a new quantity for describing nonclassicality of an arbitrary optical two-mode Gaussian state which remains invariant under any global photon-number preserving unitary transformation of the covariance matrix of the state. The…

Quantum Physics · Physics 2016-07-08 Ievgen I. Arkhipov , Jan Peřina , Jiří Svozilík , Adam Miranowicz

We provide a coherence-based approach to nonclassical behavior by means of distance measures. We develop a quantitative relation between coherence and nonclassicality quantifiers, which establish the nonclassicality as the maximum…

Quantum Physics · Physics 2022-07-20 Laura Ares , Alfredo Luis

Quantum non-Gaussian states of photons and phonons are conclusive and direct witnesses of higher-than-quadratic nonlinearities in optical and mechanical processes. Moreover, they are proven resources for quantum sensing, communication and…

Quantum Physics · Physics 2025-03-14 Lukáš Lachman , Radim Filip

Estimation of the properties of a physical system with minimal uncertainty is a central task in quantum metrology. Optical phase estimation is at the center of many metrological tasks where the value of a physical parameter is mapped to the…

Quantum Physics · Physics 2020-09-29 M. T. DiMario , F. E. Becerra

In quantum optics, nonclassical properties of various quantum states of radiation field are frequently studied. Some of those states are finite dimensional and referred to as qudits. These states are important because of their potential…

Quantum Physics · Physics 2020-11-24 Priya Malpani

Recently, Keating, Linden, and Wells \cite{KLW} showed that the density of states measure of a nearest-neighbor quantum spin glass model is approximately Gaussian when the number of particles is large. The density of states measure is the…

Mathematical Physics · Physics 2016-01-20 David Buzinski , Elizabeth Meckes

We analyze here a nonclassical state produced by an atom-cavity field interaction. The two-level atom is passed through the single-mode electromagnetic cavity field. By deforming the field operators and introducing nonlinearity to the…

Quantum Physics · Physics 2023-04-14 Naveen Kumar , Deepak , Arpita Chatterjee

The nonclassicality of single-mode quantum states is studied in relation to the entanglement created by a beam splitter. It is shown that properly defined quantifications -- based on the quantum superposition principle -- of the amounts of…

Quantum Physics · Physics 2015-06-18 W. Vogel , J. Sperling

Regular quasiprobabilities are introduced for the aim of characterizing quantum correlations of multimode radiation fields. Negativities of these quantum-correlation quasiprobabilities are necessary and sufficient for any quantum…

Quantum Physics · Physics 2013-03-15 E. Agudelo , J. Sperling , W. Vogel

We re-examine the semiclassical approximation to quantum gravity in the canonical formulation, focusing on the definition of a quasiclassical state for the gravitational field. It is shown that a state with classical correlations must be a…

General Relativity and Quantum Cosmology · Physics 2010-11-01 Gilad Lifschytz , Samir D. Mathur , Miguel E. Ortiz

Telecommunication wavelength with well-developed optical communication technologies and low losses in the waveguide are advantageous for quantum applications. However, an experimental generation of non-classical states called non-Gaussian…

Necessary and sufficient conditions for the nonclassicality of bosonic quantum states are formulated by introducing nonclassicality filters and nonclassicality quasiprobability distributions. Regular quasiprobabilities are constructed from…

Quantum Physics · Physics 2015-03-14 T. Kiesel , W. Vogel

We introduce a new density for the representation of quantum states on phase space. It is constructed as a weighted difference of two smooth probability densities using the Husimi function and first-order Hermite spectrograms. In contrast…

Mathematical Physics · Physics 2016-03-07 Johannes Keller , Caroline Lasser , Tomoki Ohsawa