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Related papers: Quantum Noise and Superluminal Propagation

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Motional narrowing refers to the striking phenomenon where the resonance line of a system coupled to a reservoir becomes narrower when increasing the reservoir fluctuation. A textbook example is found in nuclear magnetic resonance, where…

Experimentally fixed sound pulse beyond of light speed in the region of anomalous dispersion [W. M. Robertson, e. a. Appl. Phys. Lett, 90, 014102 (2007)] can be explained, as well as the similar superluminal phenomena, by "the nonlocality…

Classical Physics · Physics 2007-07-12 M. E. Perel'man

Phonons have long been thought to be incapable of explaining key phenomena in strange metals, including linear-in-\textit{T} Planckian resistivity from high to very low temperatures. We argue that these conclusions were based on static,…

Even though measurement results obtained in the real world are generally both noisy and continuous, quantum measurement theory tends to emphasize the ideal limit of perfect precision and quantized measurement results. In this article, a…

Quantum Physics · Physics 2008-12-18 Holger F. Hofmann

The ability to control the speed and polarisation of light pulses will allow for faster data flow in optical networks of the future. Optical delay and switching have been achieved using slow-light techniques in various media, including…

Atomic Physics · Physics 2009-04-08 Paul Siddons , Nia C Bell , Yifei Cai , Charles S Adams , Ifan G Hughes

Quantum systems are inherently susceptible to noise -- a notorious factor that induces decoherence and limits the performance of quantum applications. To mitigate its detrimental effects, various techniques have been developed, including…

Quantum Physics · Physics 2025-05-21 Yu-Bo Hou , Xiaoan Ai , Ruizhe You , Changchun Zhong

Radio emission from pulsars is known to exhibit a diverse range of emission phenomena, among which nulling, where the emission becomes temporarily undetectable, is an intriguing one. Observations suggest nulling is prevalent in many…

High Energy Astrophysical Phenomena · Physics 2025-12-11 Garvit Grover , N. D. Ramesh Bhat , Samuel J. McSweeney , Christopher P. Lee , Chia Min Tan , Shih Ching Fu , Bradley W. Meyers

We discuss the issue of measuring the mean position (center-of-mass) of a group of bosonic or fermionic quantum particles, including particle number fluctuations. We introduce a standard quantum limit for these measurements at ultra-low…

Other Condensed Matter · Physics 2010-07-09 Timothy Vaughan , Peter Drummond , Gerd Leuchs

We identify significant quantum many-body effects, robust to position fluctuations and strong dipole--dipole interactions, in the forward light scattering from planar arrays and uniform-density disks of cold atoms, by comparing stochastic…

Quantum Physics · Physics 2020-08-18 Robert J. Bettles , Mark D. Lee , Simon A. Gardiner , Janne Ruostekoski

We investigate quantum and quantum-relativistic effects associated with the noise power spectrum and the fluctuation--dissipation relation between current--noise spectra and linear--response conductance at low frequencies of the…

Mesoscale and Nanoscale Physics · Physics 2025-10-17 Lino Reggiani , Federico Intini , Luca Varani

Quantum metrology employs quantum effects to attain a measurement precision surpassing the limit achievable in classical physics. However, it was previously found that the precision returns the shot-noise limit (SNL) from the ideal Zeno…

Quantum Physics · Physics 2019-07-26 Kai Bai , Zhen Peng , Hong-Gang Luo , Jun-Hong An

The quantum optics of metamaterials starts with the question whether the same effective-medium theories apply as in classical optics. In general the answer is negative. For active plasmonics but also for some passive metamaterials, we show…

Quantum Physics · Physics 2023-01-27 Ehsan Amooghorban , Martijn Wubs

The sub-luminal phase velocity of electromagnetic waves in free space is generally unobtainable, being closely linked to forbidden faster than light group velocities. The requirement of effective sub-luminal phase-velocity in laser-driven…

Accelerator Physics · Physics 2017-11-01 D. A. Walsh , D. S. Lake , E. W. Snedden , M. J. Cliffe , D. M. Graham , S. P. Jamison

The idea that the existence of a consistent UV completion satisfying the fundamental axioms of local quantum field theory or string theory may impose positivity constraints on the couplings of the leading irrelevant operators in a…

High Energy Physics - Theory · Physics 2008-11-26 G. M. Shore

Einstein's theory of special relativity(SR) and the principle of causality imply that the speed of any moving object can not exceed that of light in a vacuum($c$).However,there were many attempts in literature discussing the particle moving…

High Energy Physics - Phenomenology · Physics 2007-05-23 Guang-jiong Ni

The slowdown of optical pulses due to quantum-coherence effects is investigated theoretically for an "active material" consisting of InGaAs-based double quantum-dot molecules. These are designed to exhibit a long lived coherence between two…

Mesoscale and Nanoscale Physics · Physics 2014-04-11 Stephan Michael , Weng W. Chow , Hans Christian Schneider

This paper is the first of a series of papers constraining cosmological parameters with weak lensing peak statistics using $\sim 450~\rm deg^2$ of imaging data from the Kilo Degree Survey (KiDS-450). We measure high signal-to-noise ratio…

While particles cannot travel faster than the speed of light, nor can information, this assumption has over the years been frequently questioned. Most recently, it has been argued [New J. Phys. 22, 033038 (2020)] that in a world with…

Quantum Physics · Physics 2026-05-29 Amrapali Sen , Matthias Salzger , Łukasz Rudnicki

The success of non-linear optics relies largely on pulse-to-pulse consistency. In contrast, covariance based techniques used in photoionization electron spectroscopy and mass spectrometry have shown that wealth of information can be…

We investigate nonlinear Kerr-induced coherence effect on a superluminal probing light pulse in a gain-assisted N-type 4-level atomic system via an intense monochromatic laser field. The dispersion exhibits a novel, interesting and useful…

Optics · Physics 2013-11-28 Bakht Amin Bacha , Fazal Ghafoor
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