The Experts below are selected from a list of 312 Experts worldwide ranked by ideXlab platform
Simone De Liberato - One of the best experts on this subject based on the ideXlab platform.
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Virtual photons in the ground state of a Dissipative System
Nature communications, 2017Co-Authors: Simone De LiberatoAbstract:Much of the novel physics predicted to be observable in the ultrastrong light–matter coupling regime rests on the hybridisation between states with different numbers of excitations, leading to a population of virtual photons in the System’s ground state. In this article, exploiting an exact diagonalisation approach, we derive both analytical and numerical results for the population of virtual photons in presence of arbitrary losses. Specialising our results to the case of Lorentzian resonances we then show that the virtual photon population is only quantitatively affected by losses, even when those become the dominant energy scale. Our results demonstrate most of the ultrastrong-coupling phenomenology can be observed in loss-dominated Systems which are not even in the standard strong coupling regime. We thus open the possibility to investigate ultrastrong-coupling physics to platforms that were previously considered unsuitable due to their large losses. Phenomena linked with ultrastrong coupling rely on the presence of virtual photons in the System’s ground state. In this article, using exact diagonalization, De Liberato shows that the population of ground state virtual photons is only quantitatively affected by losses.
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virtual photons in the ground state of a Dissipative System
Nature Communications, 2017Co-Authors: Simone De LiberatoAbstract:Much of the novel physics predicted to be observable in the ultrastrong light-matter coupling regime rests on the hybridisation between states with different numbers of excitations, leading to a population of virtual photons in the System's ground state. In this article, exploiting an exact diagonalisation approach, we derive both analytical and numerical results for the population of virtual photons in presence of arbitrary losses. Specialising our results to the case of Lorentzian resonances we then show that the virtual photon population is only quantitatively affected by losses, even when those become the dominant energy scale. Our results demonstrate most of the ultrastrong-coupling phenomenology can be observed in loss-dominated Systems which are not even in the standard strong coupling regime. We thus open the possibility to investigate ultrastrong-coupling physics to platforms that were previously considered unsuitable due to their large losses.
A. Couairon - One of the best experts on this subject based on the ideXlab platform.
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Propagating Pattern Selection and Causality Reconsidered
Physical Review Letters, 2000Co-Authors: Jean-marc Chomaz, A. CouaironAbstract:Pattern selection, occurring when a nonuniform state of a nonlinear Dissipative System propagates into an initially unstable, homogeneous basic state is reconsidered by application of the causality principle. In particular, the nonlinear marginal stability criterion that determines the selection of a nonlinear front solution is replaced by an exact general necessary condition that has never been considered before. The demonstration is based on the causal signaling problem derived in the context of plasma physics.
Jean-marc Chomaz - One of the best experts on this subject based on the ideXlab platform.
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Propagating Pattern Selection and Causality Reconsidered
Physical Review Letters, 2000Co-Authors: Jean-marc Chomaz, A. CouaironAbstract:Pattern selection, occurring when a nonuniform state of a nonlinear Dissipative System propagates into an initially unstable, homogeneous basic state is reconsidered by application of the causality principle. In particular, the nonlinear marginal stability criterion that determines the selection of a nonlinear front solution is replaced by an exact general necessary condition that has never been considered before. The demonstration is based on the causal signaling problem derived in the context of plasma physics.
Harvey Gould - One of the best experts on this subject based on the ideXlab platform.
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effective ergodicity breaking phase transition in a driven Dissipative System
Physical Review E, 2020Co-Authors: Sakib Matin, Chonkit Pun, Harvey Gould, W KleinAbstract:We show that the Olami-Feder-Christensen model exhibits an effective ergodicity breaking transition as the noise is varied. Above the critical noise, the System is effectively ergodic because the time-averaged stress on each site converges to the global spatial average. In contrast, below the critical noise, the stress on individual sites becomes trapped in different limit cycles, and the System is not ergodic. To characterize this transition, we use ideas from the study of dynamical Systems and compute recurrence plots and the recurrence rate. The order parameter is identified as the recurrence rate averaged over all sites and exhibits a jump at the critical noise. We also use ideas from percolation theory and analyze the clusters of failed sites to find numerical evidence that the transition, when approached from above, can be characterized by exponents that are consistent with hyperscaling.
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prediction in a driven Dissipative System displaying a continuous phase transition using machine learning
Physical Review E, 2020Co-Authors: Chonkit Pun, Sakib Matin, Harvey Gould, W KleinAbstract:Prediction in complex Systems at criticality is believed to be very difficult, if not impossible. Of particular interest is whether earthquakes, whose distribution follows a power-law (Gutenberg-Richter) distribution, are in principle unpredictable. We study the predictability of event sizes in the Olmai-Feder-Christensen model at different proximities to criticality using a convolutional neural network. The distribution of event sizes satisfies a power law with a cutoff for large events. We find that predictability decreases as criticality is approached and that prediction is possible only for large, nonscaling events. Our results suggest that earthquake faults that satisfy Gutenberg-Richter scaling are difficult to forecast.
Michael Crescimanno - One of the best experts on this subject based on the ideXlab platform.
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Quantum mechanics and thermal noise in Dissipative Systems
Annals of Physics, 1993Co-Authors: Michael CrescimannoAbstract:Abstract We study the density matrix for Systems with an arbitrary linear Dissipative mechanism at finite temperature. We show how one may derive the tunneling Lagrangians using general methods in statistical mechanics. The derivation is phenomenological in nature and as such does not proceed from any particular microphysical description of a heat bath. Correspondingly, it is also a more general framework for studying other types of noise in quantum mechanical Systems. For the special case of a linearly Dissipative System we explicitly show how this method yields the formulae of Grabert et al . (Grabert, Weiss, and Hanggi. Phys. Rev. Lett. 52 (1984), 2193; Grabert, Olschowski, and Weiss, Phys. Rev. B 36 (1981), 1931). The appendix is a description of the phenomenological approach starting with a particular microphysical model of a linearly Dissipative System.