Accurate numerical verification of the instanton method for macroscopic quantum tunneling: dynamics of phase slips
arXiv:0908.2592 · doi:10.1103/PhysRevB.82.094304
Abstract
Instanton methods, in which imaginary-time evolution gives the tunneling rate, have been widely used for studying quantum tunneling in various contexts. Nevertheless, how accurate instanton methods are for the problems of macroscopic quantum tunneling (MQT) still remains unclear because of lack of their direct comparison with exact time evolution of the many-body Schroedinger equation. Here, we verify instanton methods applied to coherent MQT. Specifically applying the quasi-exact numerical method of time-evolving block decimation to the system of bosons in a ring lattice, we directly simulate the real-time quantum dynamics of supercurrents, where a coherent oscillation between two macroscopically distinct current states occurs due to MQT. The tunneling rate extracted from the coherent oscillation is compared with that given by the instanton method. We show that the error is within 10% when the effective Planck's constant is sufficiently small. We also discuss phase slip dynamics associated with the coherent oscillations.
19 pages, 14 figures, 1 table
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Cited by in corpus (13)
- Nonequilibrium Phase Diagram of a Driven-Dissipative Many-Body System
- Optimal Persistent Currents for Interacting Bosons on a Ring with a Gauge Field
- Superfluid to Mott insulator transition in the one-dimensional Bose-Hubbard model for arbitrary integer filling factors
- Macroscopic Quantum Tunneling Escape of Bose-Einstein Condensates
- Quantum phase slips in one-dimensional superfluids in a periodic potential
- Mesoscopic Vortex-Meissner currents in ring ladders
- Flux quench in a system of interacting spinless fermions in one dimension
- Universal damping behavior of dipole oscillations of one-dimensional ultracold gases induced by quantum phase slips
- Time-dependent currents of 1D bosons in an optical lattice
- Entangled Dynamics in Macroscopic Quantum Tunneling of Bose-Einstein Condensates
- Quantum damping of Fermi-Pasta-Ulam revivals in ultracold Bose gases
- Strong correlations in quantum vortex nucleation of ultracold atomic gases
- Persistent-current states originating from the Hilbert space fragmentation in momentum space