Domain-wall melting in ultracold boson systems with holes and spin-flip defects

Abstract

Quantum magnetism is a fundamental phenomenon of nature. As of late, it has garnered a lot of interest because experiments with ultracold atomic gases in optical lattices could be used as a simulator for phenomena of magnetic systems. A paradigmatic example is the time evolution of a domain-wall state of a spin-1/2 Heisenberg chain, the so-called domain-wall melting. The model can be implemented by having two species of bosonic atoms with unity filling and strong on-site repulsion U in an optical lattice. In this paper, we study the domain-wall melting in such a setup on the basis of the time-dependent density matrix renormalization group (tDMRG). We are particularly interested in the effects of defects that originate from an imperfect preparation of the initial state. Typical defects are holes (empty sites) and flipped spins. We show that the dominating effects of holes on observables like the spatially resolved magnetization can be taken account of by a linear combination of spatially shifted observables from the clean case. For sufficiently large U, further effects due to holes become negligible. In contrast, the effects of spin flips are more severe as their dynamics occur on the same time scale as that of the domain-wall melting itself. It is hence advisable to avoid preparation schemes that are based on spin-flips.

15 pages, 12 figures. Supplemental Material: 2 animations (avi) comparing the domain-wall melting with and without defects, corresponding to figures 3, 4 and the discussion in section V.B; minor improvements; published version

References in corpus (16)

• Many-Body Physics with Ultracold Gases
• Quantum phase transition from a superfluid to a Mott insulator in a gas of ultracold atoms
• Direct observation of Anderson localization of matter-waves in a controlled disorder
• Real time evolution using the density matrix renormalization group
• Single-Atom Resolved Fluorescence Imaging of an Atomic Mott Insulator
• Single-Spin Addressing in an Atomic Mott Insulator
• Time-resolved Observation and Control of Superexchange Interactions with Ultracold Atoms in Optical Lattices
• From density-matrix renormalization group to matrix product states
• Anderson Localization of Expanding Bose-Einstein Condensates in Random Potentials
• Experimental demonstration of single-site addressability in a two-dimensional optical lattice
• Time-step targetting methods for real-time dynamics using DMRG
• Time evolution algorithms for Matrix Product States and DMRG
• Relaxation dynamics in the gapped XXZ spin-1/2 chain
• Spin dynamics for bosons in an optical lattice
• Magnetism, coherent many-particle dynamics, and relaxation with ultracold bosons in optical superlattices
• Quantum Spinon Oscillations

Cited by in corpus (13)

• Quantum gas microscopy of Kardar-Parisi-Zhang superdiffusion
• Dynamical Quasicondensation of Hard-Core Bosons at Finite Momenta
• Entanglement spreading after a geometric quench in quantum spin chains
• Domain-wall melting in the spin-$1/2$ XXZ spin chain: emergent Luttinger liquid with fractal quasi-particle charge
• A class of states supporting diffusive spin dynamics in the isotropic Heisenberg model
• Exact hydrodynamic solution of a double domain wall melting in the spin-1/2 XXZ model
• Robustness of gauge-invariant dynamics against defects in ultracold-atom gauge theories
• Sudden expansion and domain-wall melting of strongly interacting bosons in two-dimensional optical lattices and on multileg ladders
• Scaling of fronts and entanglement spreading during a domain wall melting
• Propagation of a single hole defect in the one-dimensional Bose-Hubbard model
• Magnetic phase transition in coherently coupled Bose gases in optical lattices
• Scale-invariant relaxation dynamics in two-component Bose-Einstein condensates with large particle-number imbalance
• Quasicondensation and off-diagonal long-range order of hard-core bosons during a free expansion