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Related papers: A geometric measure of non-classicality

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We theoretically generate nonclassical states from coherent state heralded by Knill-Laflamme-Milburn (KLM)-type SU(3) interference. Injecting a coherent state in signal mode and two single-photon sources in other two auxiliary modes of…

Quantum Physics · Physics 2016-06-29 Xue-xiang Xu , Shan-jun Ma

Generation of highly non-classical quantum states of light is essential for optical quantum information processing and quantum metrology. Given the lack of sufficiently strong nonlinear interactions between optical fields, the commonly…

Quantum Physics · Physics 2026-04-29 Jaromír Fiurášek

We present a method for the experimental measurement of nonclassicality witnesses and demonstrate its application. Our proposal only requires the coherent displacement of the initial state, which can be achieved by overlapping the latter…

Quantum Physics · Physics 2015-06-05 T. Kiesel , W. Vogel

We study quantum and classical systems associated with the quantum corner symmetry group $\mathrm{QCS}=\widetilde{\mathrm{SL}}(2,\mathbb{R})\ltimes \mathrm{H}_3,$ which arises in the context of quantum gravity. We relate quantum observables…

High Energy Physics - Theory · Physics 2026-03-03 Ludovic Varrin

In the standard geometric approach, the entanglement of a pure state is $\sin^2\theta$, where $\theta$ is the angle between the entangled state and the closest separable state of products of normalised qubit states. We consider here a…

Quantum Physics · Physics 2015-05-18 M. E. Carrington , R. Kobes , G. Kunstatter , D. Ostapchuk , G. Passante

Quantum technologies are powered by platforms to generate complex non-classical states of matter or light to realize applications. We investigate the non-classical properties of high-harmonic generation in semiconductors, an emerging…

Quantum Physics · Physics 2026-03-18 David Theidel , Mackrine Nahra , Ilya Karuseichyk , Houssna Griguer , Mateusz Weis , Hamed Merdji

Nonclassicality, defined in the quantum optical sense, serves as a resource for photon-based quantum technologies. Therefore, certifying the nonclassicality of a quantum state is crucial for gauging its potential for quantum advantage.…

The evolution of quantum states influenced by semiclassical gravity is distinct from that in quantum gravity theory due to the presence of a state-dependent gravitational potential. This state-dependent potential introduces nonlinearity…

Quantum Physics · Physics 2025-03-14 Yubao Liu , Wenjie Zhong , Yanbei Chen , Yiqiu Ma

Husimi function (Q-function) of a quantum state is the distribution function of the density operator in the coherent state representation. It is widely used in theoretical research, such as in quantum optics. The Wehrl entropy is the…

Quantum Physics · Physics 2025-07-14 Chen Xu , Yiqi Yu , Peng Zhang

Nonclassical state is an essential resource for quantum-enhanced communication, computing and metrology to outperform their classical counterpart. The nonclassical states that can operate at high bandwidth and room temperature while being…

Quantum Physics · Physics 2018-08-09 Jian-Peng Dou , Ai-Lin Yang , Mu-Yan Du , Di Lao , Hang Li , Xiao-Ling Pang , Jun Gao , Lu-Feng Qiao , Hao Tang , Xian-Min Jin

We analyze the polarization of a quantum radiation field under a de-Gaussification process. Specifically, we consider the addition of photons to a two-mode thermal state to get mixed non-Gaussian and nonclassical states which are still…

Quantum Physics · Physics 2018-09-28 Iulia Ghiu , Paulina Marian , Tudor A. Marian

We discuss some basic tools for an analysis of one-dimensionalquantum systems defined on a cyclic coordinate space. The basic features of the generalized coherent states, the complexifier coherent states are reviewed. These states are then…

Quantum Physics · Physics 2008-11-26 B. Bahr , H. J. Korsch

We introduce a novel measure to quantify the non-Gaussian character of a quantum state: the quantum relative entropy between the state under examination and a reference Gaussian state. We analyze in details the properties of our measure and…

Quantum Physics · Physics 2009-01-07 Marco G. Genoni , Matteo G. A. Paris , Konrad Banaszek

Distinguishability theory is developed for quantum interference of the squeezed vacuum states on unitary linear interferometers. It is found that the entanglement of photon pairs over the Schmidt modes is one of the sources of…

Quantum Physics · Physics 2022-06-03 Valery Shchesnovich

We introduce a general method for the construction of quasiprobability representations for arbitrary notions of quantum coherence. Our technique yields a nonnegative probability distribution for the decomposition of any classical state.…

Quantum Physics · Physics 2018-06-22 J. Sperling , I. A. Walmsley

High-harmonic generation is a light up-conversion process occurring in a strong laser field, leading to coherent bursts of extreme ultrashort broadband radiation [1]. As a new perspective, we propose that ultrafast strong-field electronic…

We study the properties of a non-Gaussian density matrix for a O(N) scalar field in the context of the incomplete description picture. This is of relevance for studies of decoherence and entropy production in quantum field theory. In…

Quantum Physics · Physics 2011-06-13 F. Gautier , J. Serreau

In the context of the Oppenheim-Horodecki paradigm of nonclassical correlation, a bipartite quantum state is (properly) classically correlated if and only if it is represented by a density matrix having a product eigenbasis. On the basis of…

Quantum Physics · Physics 2011-06-24 Akira SaiToh , Robabeh Rahimi , Mikio Nakahara

We discuss a phase space description of the photon number distribution of non classical states which is based on Husimi's $Q(\alpha)$ function and does not rely in the WKB approximation. We illustrate this approach using the examples of…

Quantum Physics · Physics 2009-11-10 D. F. Mundarain , J. Stephany

We construct a generalized version of the photon-subtracted squeezed vacuum states (PSSVS), which can be utilized to construct the same for nonlinear, deformed and any usual quantum mechanical models beyond the harmonic oscillator. We apply…

Quantum Physics · Physics 2020-08-28 Sanjib Dey , Sarika S. Nair