Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

arXiv:0801.4964 · Physical Review Letters

Pulsating Instability of a Bose-Einstein Condensate in an Optical Lattice

Uttam Shrestha, Marijan Koštrun, Juha Javanainen

Published Aug 15, 2008• 10 citations
arXivHTMLPDF

Abstract

We find numerically that in the limit of weak atom-atom interactions a Bose-Einstein condensate in an optical lattice may develop a pulsating dynamical instability in which the atoms nearly periodically form a peak in the occupation numbers of the lattice sites, and then return to the unstable initial state. Multiple peaks behaving similarly are also found. Simple arguments show that the pulsating instability is a remnant of integrability, and give a handle on the relevant physical scales.

DOI
10.1103/physrevlett.101.070406

Related papers

Classical and quantum dynamics of pulsating instability in a Bose-Einstein condensate in an optical lattice

Uttam Shrestha

We study the dynamics of a Bose-Einstein condensate (BEC) in a one dimensional optical lattice in the limit of weak atom-atom interactions. Numerically we find that a BEC may develop a pulsating instability in which atoms nearly periodically collect themselves into a pulse and subsequently disperse back into the initial homogeneous state. A qualitative explanation of the quasi-periodic behavior is given by drawing an analogy with a double-well system. In an extension we introduce quantum effects approximately within Truncated Wigner Approximation (TWA). In pure classical mean field theory the condensate shows an undamped pulsating instability, whereas we have observed a damping in the oscillation when we average over many stochastic realizations.

arXiv:0810.4199•Oct 23, 2008•0 citations

Non-equilibrium dynamics of a Bose -Einstein condensate in an optical lattice

Uttam Shrestha

Bose-Einstein condensates (BECs) in an optical lattice driven out of equilibrium and the subsequent dynamics are investigated in the limit of weak atom-atom interactions both within the classical mean-field approximation and by incorporating an approximate model for quantum fluctuations. A prediction of pulsating dynamical instability in which atoms periodically collect together and subsequently disperse back into the initial homogeneous state is made. This instability is a unique feature of this Hamiltonian system characterized by a single unstable mode and can be considered as a remnant of the integrability of the non-integrable system. A phase-space model has been employed to incorporate the quantum fluctuations within the truncated Wigner approximation. It is observed that the quasiperiodic behavior of the pulsating dynamics persists in the individual stochastic realizations that represent the typical experimental outcomes, but the effect of quantum fluctuations is manifested in the ensemble averages of various properties of the system. Quantum effects are increasingly prominent and the revivals of the ensemble averages of the wave function become progressively weaker when the effective interaction strength is increased. Motivated by these predictions, we apply similar methods to two-component BECs. Within the mean-field model we demonstrate a spontaneous emergence of a vector soliton like structure, a bound pair of a soliton and an anti-soliton, from the homogeneous imbalanced mixture of two BEC species. This is a feature that uniquely combines phase separation, pulsating instability, and formation of a dark-bright soliton pair when the parameters involved are tuned properly. ^

•Jan 1, 2009•0 citations

Quantum dynamics of instability-induced pulsations of a Bose-Einstein condensate in an optical lattice

Uttam Shrestha, Juha Javanainen, Janne Ruostekoski

We study quantum dynamics of a Bose-Einstein condensate in a one-dimensional optical lattice in the limit of weak atom-atom interactions within the truncated Wigner approximation for a system with one dynamically unstable mode. This extends previous classical studies of a pulsating dynamical instability in which atoms periodically collect together and subsequently disperse back into the initial homogeneous state. We observe that the quasiperiodic behavior still persists in the presence of quantum fluctuations for a single realization that represents a typical experimental outcome, but ensemble averages show various manifestations of quantum statistics. Quantum effects become more prominent when the effective interaction strength is increased.

arXiv:0901.3345•Physical Review A•Apr 16, 2009•7 citations

Pulsating and Persistent Vector Solitons in a Bose-Einstein Condensate in a Lattice upon Phase Separation Instability

Uttam Shrestha, Juha Javanainen, Janne Ruostekoski

We study numerically the outcome of the phase separation instability of a dual-species Bose-Einstein condensate in an optical lattice. When only one excitation mode is unstable a bound pair of bright and dark solitonlike structures periodically appears and disappears, whereas for more than one unstable mode a persistent soliton-antisoliton pair develops. The oscillating soliton represents a regime where the two-species condensate neither remains phase-separated nor is dynamically stable.

arXiv:0903.5016•Physical Review Letters•Nov 6, 2009•24 citations

Modulational instability in Bose--Einstein condensate in optical superlattice

E. A. Sorokina, Andrei I. Maimistov

We consider the Bose-Einstein condensate trapped in optical lattice, which is formed from two kinds of deep potentials. The tight-binding approximation was used. Steady state distribution of the probability amplitudes and the site population in the one dimensional optical superlattice were found. It was shown that this solution of the equations which describe the dynamics of the Bose-Einstein condensate in superlattice is unstable at the sufficiently high density of the bosons. The expression for increment of the modulational instability was found on base of the linear stability analysis. Numerical simulation demonstrates the evolution of the steady state distributions of bosons into the space array of the solitary peaks before the chaotic regime generation.

arXiv:0712.1617•Dec 10, 2007•0 citations

Dynamical instability of a two component Bose-Einstein Condensate in an optical lattice

Mehmet Emre Taşgın, Mehmet Özgür Oktel

We investigate the dynamical instability for a two component Bose-Einstein Condensate (BEC) in an optical lattice. We assume that the two components are in sinusoidal potentials with the same period but different phases. We find a swallow-tail type instability near the band edge, however an extra tail is formed due to the inter-component interaction. Depending on the phase difference of the potentials, the instability region may expand or shrink with increasing inter-component interaction.

Journal of Physics Conference Series•Apr 1, 2006•1 citation
We find numerically that in the limit of weak atom-atom interactions a Bose-Einstein condensate in an optical lattice may develop a pulsating dynamical instability in which the atoms nearly periodically form a peak in the occupation numbers of the lattice sites, and then return to the unstable initial state. Multiple peaks behaving similarly are also found. Simple arguments show that the pulsating instability is a remnant of integrability, and give a handle on the relevant physical scales.
We study the dynamics of a Bose-Einstein condensate (BEC) in a one dimensional optical lattice in the limit of weak atom-atom interactions. Numerically we find that a BEC may develop a pulsating instability in which atoms nearly periodically collect themselves into a pulse and subsequently disperse back into the initial homogeneous state. A qualitative explanation of the quasi-periodic behavior is given by drawing an analogy with a double-well system. In an extension we introduce quantum effects approximately within Truncated Wigner Approximation (TWA). In pure classical mean field theory the condensate shows an undamped pulsating instability, whereas we have observed a damping in the oscillation when we average over many stochastic realizations.
Bose-Einstein condensates (BECs) in an optical lattice driven out of equilibrium and the subsequent dynamics are investigated in the limit of weak atom-atom interactions both within the classical mean-field approximation and by incorporating an approximate model for quantum fluctuations. A prediction of pulsating dynamical instability in which atoms periodically collect together and subsequently disperse back into the initial homogeneous state is made. This instability is a unique feature of this Hamiltonian system characterized by a single unstable mode and can be considered as a remnant of the integrability of the non-integrable system. A phase-space model has been employed to incorporate the quantum fluctuations within the truncated Wigner approximation. It is observed that the quasiperiodic behavior of the pulsating dynamics persists in the individual stochastic realizations that represent the typical experimental outcomes, but the effect of quantum fluctuations is manifested in the ensemble averages of various properties of the system. Quantum effects are increasingly prominent and the revivals of the ensemble averages of the wave function become progressively weaker when the effective interaction strength is increased. Motivated by these predictions, we apply similar methods to two-component BECs. Within the mean-field model we demonstrate a spontaneous emergence of a vector soliton like structure, a bound pair of a soliton and an anti-soliton, from the homogeneous imbalanced mixture of two BEC species. This is a feature that uniquely combines phase separation, pulsating instability, and formation of a dark-bright soliton pair when the parameters involved are tuned properly. ^
We study quantum dynamics of a Bose-Einstein condensate in a one-dimensional optical lattice in the limit of weak atom-atom interactions within the truncated Wigner approximation for a system with one dynamically unstable mode. This extends previous classical studies of a pulsating dynamical instability in which atoms periodically collect together and subsequently disperse back into the initial homogeneous state. We observe that the quasiperiodic behavior still persists in the presence of quantum fluctuations for a single realization that represents a typical experimental outcome, but ensemble averages show various manifestations of quantum statistics. Quantum effects become more prominent when the effective interaction strength is increased.
We consider the Bose-Einstein condensate trapped in optical lattice, which is formed from two kinds of deep potentials. The tight-binding approximation was used. Steady state distribution of the probability amplitudes and the site population in the one dimensional optical superlattice were found. It was shown that this solution of the equations which describe the dynamics of the Bose-Einstein condensate in superlattice is unstable at the sufficiently high density of the bosons. The expression for increment of the modulational instability was found on base of the linear stability analysis. Numerical simulation demonstrates the evolution of the steady state distributions of bosons into the space array of the solitary peaks before the chaotic regime generation.