Searcharxiv⌕ Search

arXiv · cond-mat/0411403

One-dimensional density waves of ultracold bosons in an optical lattice

Abstract

We investigate the propagation of density-wave packets in a Bose-Hubbard model using the adaptive time-dependent density-matrix renormalization group method. We discuss the decay of the amplitude with time and the dependence of the velocity on density, interaction strength and the height of the perturbation in a numerically exact way, covering arbitrary interactions and amplitudes of the perturbation. In addition, we investigate the effect of self-steepening due to the amplitude dependence of the velocity and discuss the possibilities for an experimental detection of the moving wave packet in time of flight pictures. By comparing the sound velocity to theoretical predictions, we determine the limits of a Gross-Pitaevskii or Bogoliubov type description and the regime where repulsive one-dimensional Bose gases exhibit fermionic behaviour.

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

C. Kollath, U. Schollwöck, J. von Delft, W. Zwerger. 2004-11-16. One-dimensional density waves of ultracold bosons in an optical lattice. https://doi.org/10.1103/physreva.71.053606

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related papers

Current control of spin-wave transport in YIG via the $\small\mathbf{VO}_{\mathbf{2}}$ insulator-to-metal transition

Electrically reconfigurable spin-wave transport is central to realizing energy-efficient magnonic information technologies, yet existing current-driven approaches require current densities that undermine the fundamental dissipation advantage of spin-wave-based signal processing. Here, we demonstrate low-power electrical control of spin-wave propagation in a hybrid magnonic device comprising a low-damping yttrium iron garnet (YIG) film coupled to an adjacent vanadium dioxide ($\small\text{VO}_{2}$) stripe. Passing a small current through $\small\text{VO}_{2}$ triggers its insulator-to-metal transition (IMT), producing a sharp, reversible resistivity reduction exceeding three orders of magnitude. This abrupt phase transition locally modifies the spin-wave dispersion in YIG, reducing the group velocity and suppressing transmission by up to 40 dB near the ferromagnetic resonance frequency. Pulsed current excitation enables reconfiguration of spin-wave transport on a 10 ms timescale. Temperature-dependent measurements, corroborated by thermal modeling, decouple the respective contributions of current-induced heating of YIG and the IMT in $\small\text{VO}_{2}$, establishing the latter as the dominant control mechanism. Our results demonstrate that electrically induced phase transitions in correlated oxides constitute an energy-efficient strategy for dynamic spin-wave manipulation, providing a scalable route toward reconfigurable magnonic devices.

cond-mat.other↗

Galilean electrodynamics fluctuation in a superfluid: from general coordinate invariance to Tkachenko mode

We explore coupling the Galilean electrodynamics (GED) to an s-wave superfluid. Governed by the general coordinate invariance, the proposed effective Lagrangian hosts an unconventional superfluid whose mass is shifted by the GED gauge multiplet. We compute its electromagnetic and gravitational responses in the linear regime. In the long-wavelength limit, we discover a vanishing pressure response, and remarkably the collective mode assumes a quadratic dispersion relation reminiscent of the Tkachenko mode in an oscillating vortex lattice in (2+1) dimensions. We further demonstrate that the soft sector of the vortex lattice model is a GED in disguise, and illustrate the relation between the gauge multiplet and the Lifshitz scalar in the lowest-Landau-level regime of the vortex lattice.

cond-mat.other↗

Synchronization and Spatiotemporal Phases in Driven Precessing Domain Walls

The dynamics of extended magnetic domain walls driven by constant and alternating magnetic fields are studied using a collective coordinate $u$-$ϕ$ model. While purely constant-field driven systems exhibit deterministic spatiotemporal chaos and roughening, the alternating component can lock the precessional frequency via Shapiro-like steps. Using linear stability analysis and Floquet theory, the phase boundaries of stable, synchronized flat wall states are mapped. By studying the nonlinear dynamics of the extended system, a rich phase diagram is identified, composed of five dynamical regimes characterized by the combination of domain wall spatial order (flat, rough, or periodic) and domain wall precession temporal order (pinned, synchronized, or unsynchronized). Notably, the macroscopic temporal order of the synchronized phases can lead to a flat domain wall or to a periodic structure dominated by a narrow band of linearly unstable modes, both with coherent precession of the domain wall magnetization, while unsynchronized phases can be flat, with coherent precession, or rough with spatiotemporal chaos and incoherent precession.

cond-mat.other↗