Kibble-Zurek mechanism (KZM) uses critical scaling to predict density of topological defects and other excitations created in second order phase transitions. We point out that simply inserting asymptotic critical exponents deduced from the immediate vicinity of the critical point to obtain predictions can lead to results that are inconsistent with a more careful KZM analysis based on causality - on the comparison of the relaxation time of the order parameter with the "time distance" from the critical point. As a result, scaling of quench-generated excitations with quench rates can exhibit behavior that is locally (i.e., in the neighborhood of any given quench rate) well approximated by the power law, but with exponents that depend on that rate, and that are quite different from the naive prediction based on the critical exponents relevant for asymptotically long quench times. Kosterlitz-Thouless scaling (that governs e.g. Mott insulator to superfluid transition in the Bose-Hubbard model in one dimension) is investigated as an example of this phenomenon.
Download full-text PDF |
Source |
|---|---|
| http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4121610 | PMC |
| http://dx.doi.org/10.1038/srep05950 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Enhanced Many-Body Quantum Scars from the Non-Hermitian Fock Skin Effect.
Phys Rev Lett
November 2024
Department of Physics, National University of Singapore, Singapore 117542, Singapore.
In contrast with extended Bloch waves, a single particle can become spatially localized due to the so-called skin effect originating from non-Hermitian pumping. Here we show that in kinetically constrained many-body systems, the skin effect can instead manifest as dynamical amplification within the Fock space, beyond the intuitively expected and previously studied particle localization and clustering. We exemplify this non-Hermitian Fock skin effect in an asymmetric version of the PXP model and show that it gives rise to ergodicity-breaking eigenstates-the non-Hermitian analogs of quantum many-body scars.
View Article and Find Full Text PDFRealization of Hilbert Space Fragmentation and Fracton Dynamics in Two Dimensions.
Phys Rev Lett
November 2024
Technical University of Munich, TUM School of Natural Sciences, Physics Department, 85748 Garching, Germany.
We propose the strongly tilted Bose-Hubbard model as a natural platform to explore Hilbert-space fragmentation (HSF) and fracton dynamics in two dimensions in a setup and regime readily accessible in optical lattice experiments. Using a perturbative ansatz, we find HSF when the model is tuned to the resonant limit of on-site interaction and tilted potential. First, we investigate the quench dynamics of this system and observe numerically that the relaxation dynamics strongly depends on the chosen initial state-one of the key signatures of HSF.
View Article and Find Full Text PDFObservation of Hilbert space fragmentation and fractonic excitations in 2D.
Nature
December 2024
Max-Planck-Institut für Quantenoptik, Garching, Germany.
The relaxation behaviour of isolated quantum systems taken out of equilibrium is among the most intriguing questions in many-body physics. Quantum systems out of equilibrium typically relax to thermal equilibrium states by scrambling local information and building up entanglement entropy. However, kinetic constraints in the Hamiltonian can lead to a breakdown of this fundamental paradigm owing to a fragmentation of the underlying Hilbert space into dynamically decoupled subsectors in which thermalization can be strongly suppressed.
View Article and Find Full Text PDFInteraction-Induced Multiparticle Bound States in the Continuum.
Phys Rev Lett
October 2024
Institute of Quantum Precision Measurement, State Key Laboratory of Radio Frequency Heterogeneous Integration, College of Physics and Optoelectronic Engineering, Shenzhen University, Shenzhen 518060, China.
Article Synopsis
- Bound states in the continuum (BICs) are localized modes within radiation continuum, first predicted for single particles but now general in many wave systems; their application in many-body quantum physics is still largely unexplored.
- Researchers predict a new type of multiparticle state in the Bose-Hubbard model, creating a quasi-BIC that behaves differently under various boundary conditions—appearing as a bound pair influenced by a third particle.
- The study reveals that modulating onsite interactions can realize Thouless pumping of these quasi-BICs, where the overall center of mass shifts while the bound pair moves oppositely in relation to a standing wave.
A multi-layer multi-configurational time-dependent Hartree approach to lattice models beyond one dimension.
J Chem Phys
October 2024
Theoretische Chemie, Fakultät für Chemie, Universität Bielefeld, Universitätsstr. 25, D-33615 Bielefeld, Germany.
The multi-layer multi-configurational time-dependent Hartree (MCTDH) approach is an efficient method to study quantum dynamics in real and imaginary time. The present work explores its potential to describe quantum fluids. The multi-layer MCTDH approach in second quantization representation is used to study lattice models beyond one dimension at finite temperatures.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!