Directed transport and localization in phase-modulated driven lattices

Abstract

We explore the dynamics of noninteracting particles loaded into a phase-modulated one-dimensional lattice formed by laterally oscillating square barriers. Tuning the parameters of the driven unit cell of the lattice selected parts of the classical phase space can be manipulated in a controllable manner. We find superdiffusion in position space for all parameters regimes. A directed current of an ensemble of particles can be created through locally breaking the spatiotemporal symmetries of the time-driven potential. Magnitude and direction of the current are tunable. Several mechanisms for transient localization and trapping of particles in different wells of the driven unit cell are presented and analyzed.

Analysis of interface conversion processes of ballistic and diffusive motion in driven superlattices

“…For a more detailed analysis of the dynamics in a uniformly driven lattice, we refer to [23] where this was done in great detail.…”

“…In fact, as long as the particles have not reached x = x mid the ensemble is superdiffusive [23], leading to a fast expansion. On the one hand, the observed average drift of the ensemble in the LB is explained easily by the positively directed transport in the LB.…”

“…While the so far mentioned works focus on only timedependent ac forces, it was found recently that a spatial dependence of these ac forces leads to a diversity of dynamical * Thomas.Wulf@physnet.uni-hamburg.de † Peter.Schmelcher@physnet.uni-hamburg.de phenomena [23][24][25]. The latter studies address the classical dynamics of particles in a lattice with a site-dependent driving.…”

“…The latter studies address the classical dynamics of particles in a lattice with a site-dependent driving. In [23] it is demonstrated how a phase-modulated lattice allows for directed transport even though the driving of each barrier on its own does not break the relevant symmetries [8]. Reference [24] shows how a ramping of the potential height in combination with a site-dependent driving leads to a patterned deposition of particles.…”

Symmetries and transport in site-dependent driven quantum lattices

“…Over the last years however it was shown for classical particles loaded into driven lattices, that a site-dependent driving can add to the already existing diversity of physical phenomena in ratchet setups [24][25][26][27][28][29][30]. In [24] for example it was shown how a protocol based on a site-dependent driving leads to the patterned deposition of particles out of a uniform initial particle distribution.…”