Soliton dynamics of an atomic spinor condensate on a ring lattice
Abstract
We study the dynamics of macroscopically coherent matter waves of an ultracold atomic spin1 or spinor condensate on a ring lattice of six sites and demonstrate the spatiotemporal internal Josephson effect. Using a discrete solitary mode of uncoupled spin components as an initial condition, the time evolution of this manybody system is found to be characterized by two dominant frequencies leading to quasiperiodic dynamics at various sites. The dynamics of spatially averaged and spinaveraged degrees of freedom, however, is periodic enabling a unique identification of the two frequencies. By increasing the spindependent atomatom interaction strength we observe a resonance state, where the ratio of the two frequencies is a characteristic integer multiple and the spinandspatial degrees of freedom oscillate in “unison”. Crucially, this resonant state is found to signal the onset of chaotic dynamics characterized by a broadband spectrum. In a ferromagnetic spinor condensate with attractive spindependent interactions, the resonance is accompanied by a transition from oscillatory to rotationaltype dynamics as the time evolution of the relative phase of the matter wave of the individual spin projections changes from bounded to unbounded.
 Publication:

Physical Review A
 Pub Date:
 March 2013
 DOI:
 10.1103/PhysRevA.87.033608
 arXiv:
 arXiv:1301.5851
 Bibcode:
 2013PhRvA..87c3608S
 Keywords:

 03.75.Lm;
 03.75.Mn;
 42.50.Lc;
 73.43.Nq;
 Tunneling Josephson effect BoseEinstein condensates in periodic potentials solitons vortices and topological excitations;
 Multicomponent condensates;
 spinor condensates;
 Quantum fluctuations quantum noise and quantum jumps;
 Quantum phase transitions;
 Condensed Matter  Quantum Gases;
 Quantum Physics
 EPrint:
 doi:10.1103/PhysRevA.87.033608