111 research outputs found
People v. Hicks: Sentencing Laws and Sex Offenses - A Disingenuous Approach by the California Supreme Court
This Casenote questions the holding in People v. Hicks, a California Supreme Court decision in December 1993, which held that sex offenders are subject to multiple full-term consecutive sentences for both non-sex and sex offenses. The author argues that this decision exceeds the interpretive limits of the sex offender sentencing statutes in California. Based on a potentially applicable statutory prohibition regarding multiple punishments, this holding is criticized for abusing the court\u27s interpretive authority. In addition, this decision is argued to open the door to a potential dramatic increase in sentences that the legislature never intended
Propagation front of correlations in an interacting Bose gas
We analyze the quench dynamics of a one-dimensional bosonic Mott insulator
and focus on the time evolution of density correlations. For these we identify
a pronounced propagation front, the velocity of which, once correctly
extrapolated at large distances, can serve as a quantitative characteristic of
the many-body Hamiltonian. In particular, the velocity allows the weakly
interacting regime, which is qualitatively well described by free bosons, to be
distinguished from the strongly interacting one, in which pairs of distinct
quasiparticles dominate the dynamics. In order to describe the latter case
analytically, we introduce a general approximation to solve the Bose-Hubbard
Hamiltonian based on the Jordan-Wigner fermionization of auxiliary particles.
This approach can also be used to determine the ground-state properties. As a
complement to the fermionization approach, we derive explicitly the
time-dependent many-body state in the noninteracting limit and compare our
results to numerical simulations in the whole range of interactions of the
Bose-Hubbard model.Comment: 16 pages, 7 figure
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Scaling Approach to Quantum Non-equilibrium Dynamics of Many-body Systems
Understanding non-equilibrium quantum dynamics of many-body systems is one of the most challenging problems in modern theoretical physics. While numerous approximate and exact solutions exist for systems in equilibrium, examples of non-equilibrium dynamics of many-body systems, which allow reliable theoretical analysis, are few and far between. In this paper we discuss a broad class of time-dependent interacting systems subject to external linear and parabolic potentials, for which the many-body Schrodinger equation can be solved using a scaling transformation. We demonstrate that scaling solutions exist for both local and nonlocal interactions and derive appropriate self-consistency equations. We apply this approach to several specific experimentally relevant examples of interacting bosons in one and two dimensions. As an intriguing result we find that weakly and strongly interacting Bose-gases expanding from a parabolic trap can exhibit very similar dynamics.Physic
Livestock as possible reservoir of Escherichia albertii in Switzerland
Escherichia albertii is an emerging zoonotic foodborne pathogen. Its prevalence, distribution, and reservoirs are not yet clearly defined. In this study, we evaluated the occurrence and genomic characteristics of E. albertii in livestock from Switzerland. A total of 515 caecal samples from sheep, cattle, calves, and fattening swine were collected between May 2022 and August 2022 at abattoir level. Using an E. albertii-specific PCR targeting the Eacdt-gene, 23,7 % (51/215) of swine from 24 different farms were positive. One (1 %) out of 100 calves showed a positive PCR result, while all samples from sheep and cattle were PCR negative. Eight E. albertii isolates could be recovered from swine samples and were analysed using whole-genome sequencing. All eight isolates belonged to ST2087 or a ST4619 group subclade, as did most genomes of the 11 available global swine isolates from public databases. These two clusters shared the presence of a virulence plasmid harboring the sitABCD and iuc genes. In summary, we demonstrate that fattening swine constitute an E. albertii reservoir in Switzerland and describe specific swine-associated lineages
Quantum Many-Body Dynamics of Coupled Double-Well Superlattices
We propose a method for controllable generation of non-local entangled pairs
using spinor atoms loaded in an optical superlattice. Our scheme iteratively
increases the distance between entangled atoms by controlling the coupling
between the double wells. When implemented in a finite linear chain of 2N
atoms, it creates a triplet valence bond state with large persistency of
entanglement (of the order of N). We also study the non-equilibrium dynamics of
the one-dimensional ferromagnetic Heisenberg Hamiltonian and show that the time
evolution of a state of decoupled triplets on each double well leads to the
formation of a highly entangled state where short-distance antiferromagnetic
correlations coexist with longer-distance ferromagnetic ones. We present
methods for detection and characterization of the various dynamically generated
states. These ideas are a step forward towards the use of atoms trapped by
light as quantum information processors and quantum simulators.Comment: 13 pages, 10 figures, references adde
Quantum quench dynamics of the sine-Gordon model in some solvable limits
In connection with the the thermalization problem in isolated quantum
systems, we investigate the dynamics following a quantum quench of the
sine-Gordon model in the Luther-Emery and the semiclassical limits. We consider
the quench from the gapped to the gapless phase as well as reversed one. By
obtaining analytic expressions for the one and two-point correlation functions
of the order parameter operator at zero-temperature, the manifestations of
integrability in the absence of thermalization in the sine-Gordon model are
studied. It is thus shown that correlations in the long time regime after the
quench are well described by a generalized Gibbs ensemble. We also consider the
case where the system is initially in contact with a reservoir at finite
temperature. The possible relevance of our results to current and future
experiments with ultracold atomic systems is also critically considered.Comment: 21 pages, no figures. To appear in New J. Phys
On the determinant representations of Gaudin models' scalar products and form factors
We propose alternative determinant representations of certain form factors
and scalar products of states in rational Gaudin models realized in terms of
compact spins. We use alternative pseudo-vacuums to write overlaps in terms of
partition functions with domain wall boundary conditions. Contrarily to
Slavnovs determinant formulas, this construction does not require that any of
the involved states be solutions to the Bethe equations; a fact that could
prove useful in certain non-equilibrium problems. Moreover, by using an
atypical determinant representation of the partition functions, we propose
expressions for the local spin raising and lowering operators form factors
which only depend on the eigenvalues of the conserved charges. These
eigenvalues define eigenstates via solutions of a system of quadratic equations
instead of the usual Bethe equations. Consequently, the current work allows
important simplifications to numerical procedures addressing decoherence in
Gaudin models.Comment: 15 pages, 0 figures, Published versio
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Quantum quenches in the anisotropic spin-\frac{1}{2} Heisenberg chain: different approaches to many-body dynamics far from equilibrium
Recent experimental achievements in controlling ultracold gases in optical lattices open a new perspective on quantum many-body physics. In these experimental setups it is possible to study coherent time evolution of isolated quantum systems. These dynamics reveal new physics beyond the low-energy properties usually relevant in solid-state many-body systems. In this paper we study the time evolution of antiferromagnetic order in the Heisenberg chain after a sudden change of the anisotropy parameter, using various numerical and analytical methods. As a generic result we find that the order parameter, which can show oscillatory or non-oscillatory dynamics, decays exponentially except for the effectively non-interacting case of the XX limit. For weakly ordered initial states we also find evidence for an algebraic correction to the exponential law. The study is based on numerical simulations using a numerical matrix product method for infinite system sizes (iMPS), for which we provide a detailed description and an error analysis. Additionally, we investigate in detail the exactly solvable XX limit. These results are compared to approximative analytical approaches including an effective description by the XZ-model as well as by mean-field, Luttinger-liquid and sine-Gordon theories. This reveals which aspects of non-equilibrium dynamics can as in equilibrium be described by low-energy theories and which are the novel phenomena specific to quantum quench dynamics. The relevance of the energetically high part of the spectrum is illustrated by means of a full numerical diagonalization of the Hamiltonian.Physic
Quantum quenches from integrability: the fermionic pairing model
Understanding the non-equilibrium dynamics of extended quantum systems after
the trigger of a sudden, global perturbation (quench) represents a daunting
challenge, especially in the presence of interactions. The main difficulties
stem from both the vanishing time scale of the quench event, which can thus
create arbitrarily high energy modes, and its non-local nature, which curtails
the utility of local excitation bases. We here show that nonperturbative
methods based on integrability can prove sufficiently powerful to completely
characterize quantum quenches: we illustrate this using a model of fermions
with pairing interactions (Richardson's model). The effects of simple (and
multiple) quenches on the dynamics of various important observables are
discussed. Many of the features we find are expected to be universal to all
kinds of quench situations in atomic physics and condensed matter.Comment: 10 pages, 7 figure
Dephasing-induced diffusive transport in anisotropic Heisenberg model
We study transport properties of anisotropic Heisenberg model in a disordered
magnetic field experiencing dephasing due to external degrees of freedom. In
the absence of dephasing the model can display, depending on parameter values,
the whole range of possible transport regimes: ideal ballistic conduction,
diffusive, or ideal insulating behavior. We show that the presence of dephasing
induces normal diffusive transport in a wide range of parameters. We also
analyze the dependence of spin conductivity on the dephasing strength. In
addition, by analyzing the decay of spin-spin correlation function we discover
a presence of long-range order for finite chain sizes. All our results for a
one-dimensional spin chain at infinite temperature can be equivalently
rephrased for strongly-interacting disordered spinless fermions.Comment: 15 pages, 9 PS figure
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