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Full-Text Articles in Physics
Effective Microscopic Models For Sympathetic Cooling Of Atomic Gases, Roberto Onofrio, Bala Sundaram
Effective Microscopic Models For Sympathetic Cooling Of Atomic Gases, Roberto Onofrio, Bala Sundaram
Dartmouth Scholarship
Thermalization of a system in the presence of a heat bath has been the subject of many theoretical investigations especially in the framework of solid-state physics. In this setting, the presence of a large bandwidth for the frequency distribution of the harmonic oscillators schematizing the heat bath is crucial, as emphasized in the Caldeira-Leggett model. By contrast, ultracold gases in atomic traps oscillate at well-defined frequencies and therefore seem to lie outside the Caldeira-Leggett paradigm. We introduce interaction Hamiltonians which allow us to adapt the model to an atomic physics framework. The intrinsic nonlinearity of these models differentiates them from …
Information Content Of Spontaneous Symmetry Breaking, Marcelo Gleiser, Nikitas Stamatopoulos
Information Content Of Spontaneous Symmetry Breaking, Marcelo Gleiser, Nikitas Stamatopoulos
Dartmouth Scholarship
We propose a measure of order in the context of nonequilibrium field theory and argue that this measure, which we call relative configurational entropy (RCE), may be used to quantify the emergence of coherent low-entropy configurations, such as time-dependent or time-independent topological and nontopological spatially extended structures. As an illustration, we investigate the nonequilibrium dynamics of spontaneous symmetry breaking in three spatial dimensions. In particular, we focus on a model where a real scalar field, prepared initially in a symmetric thermal state, is quenched to a broken-symmetric state. For a certain range of initial temperatures, spatially localized, long-lived structures known …
Dynamical Critical Scaling And Effective Thermalization In Quantum Quenches: Role Of The Initial State, Shusa Deng, Gerardo Ortiz, Lorenza Viola
Dynamical Critical Scaling And Effective Thermalization In Quantum Quenches: Role Of The Initial State, Shusa Deng, Gerardo Ortiz, Lorenza Viola
Dartmouth Scholarship
We explore the robustness of universal dynamical scaling behavior in a quantum system near criticality with respect to initialization in a large class of states with finite energy. By focusing on a homogeneous XY quantum spin chain in a transverse field, we characterize the nonequilibrium response under adiabatic and sudden quench processes originating from a pure as well as a mixed excited initial state, and involving either a regular quantum critical or a multicritical point. We find that the critical exponents of the ground-state quantum phase transition can be encoded in the dynamical scaling exponents despite the finite energy of …
Dynamical Non-Ergodic Scaling In Continuous Finite-Order Quantum Phase Transitions, S. Deng, G. Ortiz, L. Viola
Dynamical Non-Ergodic Scaling In Continuous Finite-Order Quantum Phase Transitions, S. Deng, G. Ortiz, L. Viola
Dartmouth Scholarship
We investigate the emergence of universal dynamical scaling in quantum critical spin systems adiabatically driven out of equilibrium, with emphasis on quench dynamics which involves non-isolated critical points (i.e., critical regions) and cannot be a priori described through standard scaling arguments nor time-dependent perturbative approaches. Comparing to the case of an isolated quantum critical point, we find that non-equilibrium scaling behavior of a large class of physical observables may still be explained in terms of equilibrium critical exponents. However, the latter are in general non-trivially path-dependent, and detailed knowledge about the time-dependent excitation process becomes essential. In particular, …
Thermodynamical Approaches To Efficient Sympathetic Cooling In Ultracold Fermi-Bose Atomic Mixtures, Michael Brown-Hayes, Qun Wei, Carlo Presilla, Roberto Onofrio
Thermodynamical Approaches To Efficient Sympathetic Cooling In Ultracold Fermi-Bose Atomic Mixtures, Michael Brown-Hayes, Qun Wei, Carlo Presilla, Roberto Onofrio
Dartmouth Scholarship
We discuss the cooling efficiency of ultracold Fermi-Bose mixtures in species-selective traps using a thermodynamical approach. The dynamics of evaporative cooling trajectories is analyzed in the specific case of bichromatic optical dipole traps also taking into account the effect of partial spatial overlap between the Fermi gas and the thermal component of the Bose gas. We show that large trapping frequency ratios between the Fermi and the Bose species allow for the achievement of a deeper Fermi degeneracy, consolidating in a thermodynamic setting earlier arguments based on more restrictive assumptions. In particular, we confirm that the minimum temperature of the …
Objectivity, Information, And Maxwell's Demon, Steven Weinstein
Objectivity, Information, And Maxwell's Demon, Steven Weinstein
Dartmouth Scholarship
This paper examines some common measures of complexity, structure, and information, with an eye toward understanding the extent to which complexity or information‐content may be regarded as objective properties of individual objects. A form of contextual objectivity is proposed which renders the measures objective, and which largely resolves the puzzle of Maxwell's Demon.
Adiabatic Invariance With First Integrals Of Motion, Artur D. Adib
Adiabatic Invariance With First Integrals Of Motion, Artur D. Adib
Dartmouth Scholarship
The construction of a microthermodynamic formalism for isolated systems based on the concept of adiabatic invariance is an old but seldom appreciated effort in the literature, dating back at least to P. Hertz [Ann. Phys. (Leipzig) 33, 225 (1910)]. An apparently independent extension of such formalism for systems bearing additional first integrals of motion was recently proposed by Hans H. Rugh [Phys. Rev. E 64, 055101 (2001)], establishing the concept of adiabatic invariance even in such singular cases. After some remarks in connection with the formalism pioneered by Hertz, it will be suggested that such an extension can …