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Related papers: Genuine Continuous Quantumness

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Measurements with randomly chosen settings determine many important properties of quantum states without the need for a shared reference frame or calibration. They naturally emerge in the context of quantum communication and quantum…

It is proved that the width of a function and the width of the distribution of its values cannot be made arbitrarily small simultaneously. In the case of ergodic stochastic processes, an ensuing uncertainty relationship is demonstrated for…

Statistical Mechanics · Physics 2019-04-30 Timur E. Gureyev , Alexander Kozlov , Yakov I. Nesterets , David M. Paganin , Harry M. Quiney

The algebraic quantification of nonclassicality, which naturally arises from the quantum superposition principle, is related to properties of regular nonclassicality quasiprobabilities. The latter are obtained by non-Gaussian filtering of…

Quantum Physics · Physics 2018-05-21 B. Kühn , W. Vogel

Quantum attributes of light have been related to non-classicality so far, i. e. to incompatibility with mixtures of coherent states. The progress in quantum optics indicates that this feature does not suffice to witness exotic behavior of…

Quantum Physics · Physics 2016-12-21 Lukáš Lachman , Radim Filip

The manner in which unpredictable chaotic dynamics manifests itself in quantum mechanics is a key question in the field of quantum chaos. Indeed, very distinct quantum features can appear due to underlying classical nonlinear dynamics. Here…

Quantum Physics · Physics 2014-03-07 G. B. Lemos , R. M. Gomes , S. P. Walborn , P. H. Souto Ribeiro , F. Toscano

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…

Quantum systems can be prepared in an infinite continuum of states, but only some of them can be used as resources for quantum technologies. Discerning whether a specific quantum state falls into this class, is often a challenging task. We…

Quantum Physics · Physics 2025-09-11 Šimon Bräuer , Tomáš Opatrný , Petr Marek

Measurement outcomes of a quantum state can be genuinely random (unpredictable) according to the basic laws of quantum mechanics. The Heisenberg-Robertson uncertainty relation puts constrains on the accuracy of two noncommuting observables.…

Quantum Physics · Physics 2017-09-13 Xiao Yuan , Ge Bai , Tianyi Peng , Xiongfeng Ma

Significant achievements in the reduction of classical-noise floor will allow macroscopic systems to prepare nearly Heisenberg-Limited quantum states through a continuous measurement, i.e. conditioning. In order to probe the conditional…

Some predictions of quantum mechanics are in contrast with the macroscopic realm of everyday experience, in particular those originated by the Heisenberg uncertainty principle, encoded in the non-commutativity of some measurable operators.…

Quantum Physics · Physics 2022-02-16 A. Chowdhury , P. Vezio , M. Bonaldi , A. Borrielli , F. Marino , B. Morana , G. A. Prodi , P. M. Sarro , E. Serra , F. Marin

Quantum mechanics, through the Heisenberg uncertainty principle, imposes limits to the precision of measurement. Conventional measurement techniques typically fail to reach these limits. Conventional bounds to the precision of measurements…

Quantum Physics · Physics 2009-11-10 Vittorio Giovannetti , Seth Lloyd , Lorenzo Maccone

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

We report the direct -- continuous in phase -- sampling of a regularized $P$ function, the so-called nonclassicality quasiprobability, for squeezed light. Through their negativities, the resulting phase-space representation uncovers the…

Quantum Physics · Physics 2015-09-23 E. Agudelo , J. Sperling , W. Vogel , S. Köhnke , M. Mraz , B. Hage

Quantification of nonclassicality and entanglement in a quantum state is crucial for quantum advantage in information processing and computation. Robustness is one of the tractable measures for quantifying quantum resources. Gaussian states…

Quantum Physics · Physics 2023-09-22 Xiao-yu Chen

A unified conceptual foundation of classical and quantum physics is given, free of undefined terms. Ensembles are defined by extending the `probability via expectation' approach of Whittle to noncommuting quantities. This approach carries…

Quantum Physics · Physics 2007-05-23 Arnold Neumaier

Quantum physics exhibits an intrinsic and private form of randomness with no classical counterpart. Any setup for quantum randomness generation involves measurements acting on quantum states. In this work, we consider the following…

Quantum Physics · Physics 2025-07-29 Fionnuala Curran , Morteza Moradi , Gabriel Senno , Magdalena Stobinska , Antonio Acín

Heisenberg's uncertainty principle results in one of the strangest quantum behaviors: an oscillator can never truly be at rest. Even in its lowest energy state, at a temperature of absolute zero, its position and momentum are still subject…

Quantum Physics · Physics 2015-08-26 F. Lecocq , J. D. Teufel , J. Aumentado , R. W. Simmonds

Quantum coherence is a fundamental property of quantum systems, separating quantum from classical physics. Recently, there has been significant interest in the characterization of quantum coherence as a resource, investigating how coherence…

Quantum systems can be exploited for disruptive technologies but in practice quantum features are fragile due to noisy environments. Quantum coherence, a fundamental such feature, is a basis-dependent property that is known to exhibit a…

Although nonclassical quantum states are important both conceptually and as a resource for quantum technology, it is often difficult to test whether a given quantum system displays nonclassicality. A simple method to certify nonclassicality…

Quantum Physics · Physics 2012-10-09 T. Kiesel , W. Vogel , S. L. Christensen , J. -B. Béguin , J. Appel , E. S. Polzik