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Results for “amplification”
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Superradiant amplification in a chirped-tapered x-ray free-electron laser
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Renormalization-group approach to Kohn-Luttinger superconductivity: Amplification of the pairing gap from ℓ 4 to ℓ
Here, we revisit the renormalization group (RG) analysis of the Kohn-Luttinger (KL) mechanism for superconductivity. The KL mechanism leads to superconductivity in a system with a repulsive bare interaction. The key ingredient is the screening effect that renders the induced interaction attractive in channels with nonzero angular momentum ℓ ≠ 0, thereby triggering the Bardeen-Cooper-Schrieffer (BCS) instability. According to the original argument, the resulting gap is exponentially small, with its exponent scaling as −ℓ 4 . However, the KL mechanism was originally formulated within perturbation theory, where the series is known to converge poorly in certain cases—most notably, for the 𝑝-wave paring gap induced by a repulsive 𝑠-wave contact interaction. This poor convergence may be attributed to a divergent integrand in a specific class of diagrams containing both the BCS logarithm and the Kohn anomaly, suggesting that one must resum the Kohn anomaly contributions separately from the BCS logarithm. In this work, we incorporate the Kohn anomaly contribution into the 𝛽 function of the RG equation governing the BCS instability near the Fermi surface. Our solution shows that the KL gap exponent is then proportional to −ℓ, indicating a significant enhancement of the KL mechanism beyond the previously known result. To illustrate this, we study the spin-triplet 𝑝-wave pairing gap arising from a repulsive 𝑠-wave contact interaction and compare our RG-based results with those obtained from the Bethe-Salpeter equation in perturbation theory.
Phase transition amplification of proton number fluctuations in nuclear collisions from a transport model approach
The time evolution of particle number fluctuations in nuclear collisions at intermediate energies (E lab = 1.23–10A GeV) is studied by means of the UrQMD-3.5 transport model. The transport description incorporates baryonic interactions through a density-dependent potential. This allows for an implementation of a first-order phase transition including a mechanically unstable region at large baryon density. The scaled variance of the baryon and proton number distributions is calculated in the central cubic spatial volume of the collisions at different times. A significant enhancement of fluctuations associated with the unstable region is observed. This enhancement persists to late times, reflecting a memory effect for the fluctuations. The presence of the phase transition has a much smaller influence on the observable event-by-event fluctuations of protons in momentum space.
Terahertz Driven Amplification of Coherent Optical Phonons in GaAs Coupled to a Metasurface
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Inefficient Magnetic-Field Amplification in Supersonic Laser-Plasma Turbulence
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Eavesdropping on the Decohering Environment: Quantum Darwinism, Amplification, and the Origin of Objective Classical Reality
“How much information about a system S can one extract from a fragment F of the environment E that decohered it?” is the central question of Quantum Darwinism. To date, most answers relied on the quantum mutual information of SF, or on the Holevo bound on the channel capacity of F to communicate the classical information encoded in S. Furthermore, these are reasonable upper bounds on what is really needed but much harder to calculate—the accessible information in the fragment F about S. We consider a model based on imperfect c-not gates where all the above can be computed, and discuss its implications for the emergence of objective classical reality. We find that all relevant quantities, such as the quantum mutual information as well as various bounds on the accessible information exhibit similar behavior. In the regime relevant for the emergence of objective classical reality this includes scaling independent of the quality of the imperfect c-not gates or the size of E, and even nearly independent of the initial state of S.
Particle-in-cell simulation of plasma-based amplification using a moving window
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Parametric amplification of an optomechanical quantum interconnect
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Control and amplification of Bloch oscillations via photon-mediated interactions
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Higgs-Mediated Optical Amplification in a Nonequilibrium Superconductor
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Exciton-Condensate-Like Amplification of Energy Transport in Light Harvesting
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Compression of Terawatt Long-Wavelength Laser Pulses Through Backward Raman Amplification
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Broadband amplification in Nd3+ phosphate glass: Single effective oscillator model and beyond
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Enhanced performance of Brillouin distributed fiber sensor with hybrid amplification
Presented by NETL at SPIE Defense and Commercial Sensing 04/19
Two Methods of Amplification of Coherent Extreme Ultraviolet Radiation During Harmonic Generation in Plasmas
Different recently revealed approaches of harmonic enhancement in plasmas are reviewed. The 4-step analytical model of resonant enhancement of high-order harmonic generation is extended to the systems possessing resonant transitions of inner-shell electrons. Role of inelastic scattering is discussed by simulation of excited state’s population dynamics. The enhancement of harmonics in the In plasma using different pumps is analyzed to prove the concept. We also discuss the plasma emission and harmonic generation spectra in the case of resonance enhancement of single harmonic using various laser-produced plasmas. The analysis of these spectra showed that the enhancement of harmonics depended on the oscillator strengths of the nearby ionic transitions rather than the plasma emission transitions. Finally, we review some recent experimental studies of the phase-matching of high-order harmonic generation in multi-jet plasmas.