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Related papers: Objectivity in the quantum Brownian motion revisit…

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Operator fractional Brownian motion (OFBM) is the natural vector-valued extension of the univariate fractional Brownian motion. Instead of a scalar parameter, the law of an OFBM scales according to a Hurst matrix that affects every…

Probability · Mathematics 2015-09-17 Patrice Abry , Gustavo Didier

In this paper we investigate the Quantum Brownian motion of a point particle induced by quantum vacuum fluctuations of a massless scalar field in (3 + 1)-dimensional Minkowski spacetime with distinct conditions (Dirichlet, Neumann, mixed…

High Energy Physics - Theory · Physics 2023-05-10 Éwerton J. B. Ferreira , Eliza M. B. Guedes , Herondy F. Santana Mota

A non-Markovian stochastic Schroedinger equation for a quantum system coupled to an environment of harmonic oscillators is presented. Its solutions, when averaged over the noise, reproduce the standard reduced density operator without any…

Quantum Physics · Physics 2009-10-31 Walter T Strunz , Lajos Diosi , Nicolas Gisin

The quantum measurement axiom dictates that physical observables and in particular the Hamiltonian must be diagonalizable and have a real spectrum. For a time-independent Hamiltonian (with a discrete spectrum) these conditions ensure the…

Quantum Physics · Physics 2009-11-13 Ali Mostafazadeh

Quantum metrology is a promising application of quantum technologies, enabling the precise measurement of weak external fields at a local scale. In typical quantum sensing protocols, a qubit interacts with an external field, and the…

Quantum Physics · Physics 2025-05-09 Hideaki Kawaguchi , Yuichiro Mori , Takahiko Satoh , Yuichiro Matsuzaki

Quantum Boltzmann machines (QBMs) are machine-learning models for both classical and quantum data. We give an operational definition of QBM learning in terms of the difference in expectation values between the model and target, taking into…

Quantum Physics · Physics 2025-02-13 Luuk Coopmans , Marcello Benedetti

I give an informal overview of the decoherent histories approach to quantum mechanics, due to Griffiths, to Omn\`es, and to Gell-Mann and Hartle is given. Results on the connections between decoherence, records, correlation and entropy are…

General Relativity and Quantum Cosmology · Physics 2007-05-23 J. J. Halliwell

We establish the ultimate limits that quantum theory imposes on the accuracy attainable in optical ellipsometry. We show that the standard quantum limit, as usual reached when the incident light is in a coherent state, can be surpassed with…

Quantum Physics · Physics 2023-07-19 L. Rudnicki , L. L. Sanchez-Soto , G. Leuchs , R. W. Boyd

We study the emergence of objective properties in open quantum systems. In our analysis, the environment is promoted from a passive role of reservoir selectively destroying quantum coherence, to an active role of amplifier selectively…

Quantum Physics · Physics 2009-11-10 Harold Ollivier , David Poulin , Wojciech H. Zurek

To prepare quantum states and extract information, it is often assumed that one can perform a perfectly projective measurement. Such measurements can achieve an uncorrelated system and environment state. However, perfectly projective…

Quantum Physics · Physics 2025-06-25 Alvin Gonzales , Daniel Dilley , Mark Byrd

We consider continuous quantum measurement of a superconducting qubit in the circuit QED setup with a moderate bandwidth of the measurement resonator, i.e., when the "bad cavity" limit is not applicable. The goal is a simple description of…

Quantum Physics · Physics 2016-10-26 Alexander N. Korotkov

A new model that generalizes the study of quantum Brownian motion (BM) is constructed. We consider disordered environment that may be either static (quenched), noisy or dynamical. The Zwanzig-Caldeira-Leggett BM-model constitutes formally a…

chao-dyn · Physics 2009-10-28 Doron Cohen

The paper reviews and discusses four ideas scattered in previous papers of the author. First, objective properties of quantum systems are not associated with observables but are defined by preparations. Second, measurable results of…

Quantum Physics · Physics 2016-07-29 Petr Hajicek

Quantum metrology allows us to attain a measurement precision that surpasses the classically achievable limit by using quantum characters. The metrology precision is raised from the standard quantum limit (SQL) to the Heisenberg limit (HL)…

Quantum Physics · Physics 2017-11-21 Yuan-Sheng Wang , Chong Chen , Jun-Hong An

Quantum Information scrambling (QI-scrambling) is a pivotal area of inquiry within the study of quantum many-body systems. This research derives mathematical upper and lower bounds for the scrambling rate by applying the Maligranda…

Quantum Physics · Physics 2025-07-25 Ahmed Zahia , M. Y. Abd-Rabbou , Atta ur Rahman , Cong Feng Qiao

We consider a quantum particle subject to Ohmic dissipation, moving in a bichromatic quasiperiodic potential. In a periodic potential the particle undergoes a zero-temperature localization-delocalization transition as dissipation strength…

Quantum Gases · Physics 2019-08-14 Aaron J Friedman , Romain Vasseur , Austen Lamacraft , S. A. Parameswaran

Quantum many-body interactions can induce quantum entanglement among particles, rendering them valuable resources for quantum-enhanced sensing. In this work, we derive a universal and fundamental bound for the growth of the quantum Fisher…

Quantum Physics · Physics 2024-03-07 Hai-Long Shi , Xi-Wen Guan , Jing Yang

Asymptotic behavior of the one-dimensional Brownian motion in general random environments has been investigated by many researchers. However, many of the methods used in the argument are available only for the one-dimensional case. In this…

Probability · Mathematics 2015-07-14 Seiichiro Kusuoka , Hiroshi Takahashi , Yozo Tamura

In this work we analyse the notion of measurement non-contextuality (MNC) and identify contextual scenarios which involve sequential measurements of only a single measurement device. We show that any non-contextual ontological model fails…

Quantum Physics · Physics 2023-01-05 Jaskaran Singh , Rajendra Singh Bhati , Arvind

Contextuality - the obstruction to describing quantum mechanics in a classical statistical way - has been proposed as a resource that powers quantum computing. The measurement-based model provides a concrete manifestation of contextuality…

Quantum Physics · Physics 2018-10-12 Markus Frembs , Sam Roberts , Stephen D. Bartlett