The exponential growth of the out-of-time-ordered correlator (OTOC) has been proposed as a quantum signature classical chaos. rate is expected to coincide with Lyapunov exponent. This quantum-classical correspondence corroborated for kicked rotor and stadium billiard, which are one-body chaotic systems. conjecture not yet validated realistic systems interactions. We make progress in this direction by studying OTOC Dicke model, where two-level atoms cooperatively interact quantized radiation...

Quantum chaos refers to signatures of classical found in the quantum domain. Recently, it has become common equate exponential behavior out-of-time order correlators (OTOCs) with chaos. The quantum-classical correspondence between OTOC growth and limit indeed been corroborated theoretically for some systems there are several projects do same experimentally. Dicke model, particular, which a regular chaotic regime, is currently under intense investigation by experiments trapped ions. We show,...

We study the nonintegrable Dicke model and its integrable approximation, Tavis-Cummings model, as functions of both coupling constant excitation energy. Excited-state quantum phase transitions (ESQPT) are found analyzing density states in semiclassical limit comparing it with numerical results for case large Hilbert spaces, taking advantage efficient methods recently developed. Two different ESQPTs identified models, which signaled singularities states; one static ESQPT occurs any coupling,...

The nuclear transition matrix elements ${M}^{(0\ensuremath{\nu})}$ for the neutrinoless $\ensuremath{\beta}\ensuremath{\beta}$ decay of $^{94,96}\mathrm{Zr}$, $^{98,100}\mathrm{Mo}$, $^{104}\mathrm{Ru}$, $^{110}\mathrm{Pd}$, $^{128,130}\mathrm{Te}$, and $^{150}\mathrm{Nd}$ isotopes in case ${0}^{+}\ensuremath{\rightarrow}{0}^{+}$ are calculated using projected-Hartree-Fock-Bogoliubov wave functions, which eigenvectors four different parametrizations a Hamiltonian with pairing plus multipolar...

Samples of commercial plastics have been bombarded by short pulses nonpenetrating electrons. Observations charge transients representing the long-lived component induced current lead to following conclusions: (i) One carrier species is rapidly and strongly localized; (ii) mobile excess carriers decay bimolecular recombination; (iii) although such cannot in practice complete transits through thickness samples, they can be swept out excited layer into electrode. This paper fully explains how...

The nonintegrable Dicke model and its integrable approximation, the Tavis-Cummings model, are studied as functions of both coupling constant excitation energy. present contribution extends analysis presented in previous paper by focusing on statistical properties quantum fluctuations energy spectrum their relation with excited-state phase transitions. These compared dynamics observed semiclassical versions models. presence chaos for different energies constants is exhibited, employing...

The relation between the onset of chaos and critical phenomena, like quantum phase transitions (QPTs) excited-state (ESQPTs), is analyzed for atom-field systems. While it has been speculated that hard associated with ESQPTs based in resonant case, off-resonant cases, a close look at vicinity QPTs resonance, show clearly both chaos, respond to different mechanisms. results are supported detailed numerical study dynamics semiclassical Hamiltonian Dicke model. appearance quantified calculating...

An analysis of the classical and quantum phase transitions Lipkin-Meshkov-Glick model is presented. It shown that dynamics ruled by energy surface system. Applying catastrophe formalism to this separatrix obtained. determines regions in control parameter space where there are transitions. Special attention given compositions ground first-excited states, which well described even odd SU(2) coherent states. Phase be associated with a change wave functions from collective single-particle...

The Dicke Hamiltonian describes the simplest quantum system with atoms interacting photons: $N$ two-level inside a perfectly reflecting cavity, which allows only one electromagnetic mode. It has also been successfully employed to describe superconducting circuits that behave as artificial coupled resonator. exhibits transition superradiant phase at zero temperature. When interaction strength reaches its critical value, both number of photons and in excited states together their fluctuations,...

In the projected-Hartree-Fock-Bogoliubov (PHFB) model, uncertainties in nuclear transition matrix elements for neutrinoless double-$\ensuremath{\beta}$ decay of ${\phantom{\rule{4pt}{0ex}}}^{94,96}$Zr, ${}^{98,100}$Mo, ${}^{104}$Ru, ${}^{110}$Pd, ${}^{128,130}$Te, and ${}^{150}$Nd isotopes within mechanisms involving light Majorana neutrinos, classical Majorons, sterile neutrinos are statistically estimated by considering sets 16 (24) calculated with four different parametrizations pairing...

Quantum systems whose classical counterparts are chaotic typically have highly correlated eigenvalues and level statistics that coincide with those from ensembles of full random matrices. A dynamical manifestation these correlations comes in the form so-called correlation hole, which is a dip below saturation point survival probability's time evolution. In this work, we study hole spin-boson (Dicke) model, presents regime can be realized experiments ultracold atoms ion traps. We derive an...

Abstract The hole mobility μ has been measured in dispersions of N-isopropyl carbazole polycarbonate for relative concentrations c between 100% (PVK) and 2%. At sufficiently high temperature (T) field (F), transport is essentially coherent. For c<40%, μαc n where n≃4, i.e. non-percolative. c>10%, μαR 2exp(− 2αR), R the average spacing α≃0·62× 108cm−1, almost independent T F. c<5% F, becomes substantially greater than predicted by above relation. constant T, logμ proportional to F 1/2 rather...

We discuss the Garvey-Kelson mass relations in an extended formalism and show how they can be used to test improve consistency of most commonly formulas achieve more accurate predictions.

Published drift mobility measurements on amorphous PVK, TNF, TNF:PVK mixtures and dispersions of TNF in polyester strongly suggest that transport is by small-polaron hopping controlled charged traps. The existence a characteristic temperature at which the extrapolated loses its field dependence ascribed to permittivity. With aid first-order model Coulomb-trapping systems it argued activation energy room only 0.4-0.45 eV, not 0.65 eV as suggested experiments, trap-free order 10-3 cm2 V-1 s-1....

We show that semi-classical states adapted to the symmetry of Hamiltonian are an excellent approximation exact quantum solution ground and first excited Dicke model. Their overlap is very close 1 except in a vicinity phase transition. Furthermore, they have analytic forms terms model parameters allow us calculate analytically expectation values field matter observables. Some these differ considerably from results obtained via standard coherent states, by means Holstein-Primakoff series...

The emergence of chaos in an atom-field system is studied employing both semiclassical and numerical quantum techniques, taking advantage the algebraic character Hamiltonian. A Hamiltonian obtained by considering expectation value Glauber (for field) Bloch atoms) coherent states. Regular chaotic regions are identified looking at Poincaré sections for different energies parameter values. An analytical expression energy density states integrating available phase space, which provides exact...

This study explores the semiclassical limit of an integrable-chaotic bosonic many-body quantum system, providing nuanced insights into its behavior. We examine classical-quantum correspondences across different interaction regimes bosons in a triple-well potential, ranging from integrable to self-trapping regime, and including chaotic one. The close resemblance between phase-space mean projections classical trajectories those Husimi distributions evokes principle uniform condensation Wigner...

We present a fully quantum-mechanical, microscopic, unified treatment of ground-state band and multi-phonon $\gamma$-vibrational bands using shell model diagonalization with the triaxial projected model. The results agree very well data on g- $\gamma$-band spectra in $^{156-170}$Er, as recently measured $4^+$ 2-phonon $\gamma$-bandhead energies $^{166}$Er $^{168}$Er. Multi-phonon $\gamma$-excitation are predicted.

It has been suggested that chaotic motion inside the nucleus may significantly limit accuracy with which nuclear masses can be calculated. Using a power spectrum analysis we show inclusion of additional physical contributions in mass calculations, through many-body interactions or local information, removes signal discrepancies between calculated and measured masses. Furthermore, systematic application global formulas set relationships among neighboring nuclei to more than 2000 allows one an...

The $({\ensuremath{\beta}}^{\ensuremath{-}}{\ensuremath{\beta}}^{\ensuremath{-}}){}_{0\ensuremath{\nu}}$ decay of $^{94,96}\mathrm{Zr}$, $^{98,100}\mathrm{Mo}$, $^{104}\mathrm{Ru}$, $^{110}\mathrm{Pd}$, $^{128,130}\mathrm{Te}$, and $^{150}\mathrm{Nd}$ isotopes for the ${0}^{+}\ensuremath{\rightarrow}{0}^{+}$ transition is studied in projected Hartree-Fock-Bogoliubov framework. In our earlier work, reliability HFB intrinsic wave functions participating...

The electrical conduction in a number of commercial plastics has been studied under pulsed bombardment by fully penetrating electrons. Detailed results are given mainly for polystyrene. kinetics obeyed the ``prompt'' component induced current predominantly first order, those ``long-lived'' current, second order. generally support assumptions made Paper I, and particular confirm interpretation decay time long-lived as bimolecular recombination lifetime. A simple model radiation-induced...

Employing efficient diagonalization techniques, we perform a detailed quantitative study of the regular and chaotic regions in phase space simplest nonintegrable atom-field system, Dicke model. A close correlation between classical Lyapunov exponents quantum Participation Ratio coherent states on eigenenergy basis is exhibited for different points space. It also shown that scales linearly with number atoms its square root ones.

The thermodynamical properties of a generalized Dicke model are calculated and related with the critical its energy spectrum, namely quantum phase transitions (QPT) excited state (ESQPT). thermal both in canonical microcanonical ensembles. latter deduction allows for an explicit description relation between spectrum properties. While isolated system subspaces different pseudo spin disconnected, whole is accesible, ensamble situation radically different. multiplicity lowest states each...

We compare the entire classical and quantum evolutions of Dicke model in its regular chaotic domains. This is a paradigmatic interacting spin-boson great experimental interest. By studying survival probabilities initial coherent states, we identify features long-time dynamics that are purely discuss their impact on equilibration times. show ratio between asymptotic values probability serves as metric to determine proximity separatrix regime distinguish two manifestations chaos: scarring...