Thursday, March 23, 2006

Dynamics and Manipulation of Matter-Wave Solitons in Optical Superlattices

I am posting this entry a little belatedly (which I'm starting as I listen to the end of the song "Earth Girls Are Easy").

About a month ago, one of my papers was posted in one of the late March issues of Physics Letters A. (The corrected proof was posted online in early December, it was officially published last month, and only around now are we reaching the official date of the issue.)

This paper, called Dynamics and Manipulation of Matter-Wave Solitons in Optical Superlattices concerns fast (nonadiabatic) and slow (adiabatic) adjust of a superlattice potential to controllably move solitary waves around in a Bose-Einstein condensate. A superlattice potential can be modeled as a sum of two or more trig functions -- two in this case and the experimentally achieved case -- and experimentalists have a lot of control over the amplitudes, wave numbers, and relative phases of the different components (cosines) in the potential. One of the messages of this paper is that because of the extra length scale in a superlattice potential as compared to a regular lattice potential, one has a lot more flexibility. Soliton manipulation is one aspect of this. This business is motivated in part by quantum computing considerations (and in part by the desire to study cool nonlinear phenomena), and an experimental scion of the superlattice experiment from NIST (which is an eggshell potential: a regular optical lattice x a double well) has very recently been proposed as a possible way to get a 2-qbit computer.

My coauthors on this paper are Panos Kevrekidis, Ricardo Carretero-González, and Dmitri Frantzeskakis.

Here is the abstract:

We study the existence and stability of bright, dark, and gap matter-wave solitons in optical superlattices. Then, using these properties, we show that (time-dependent) “dynamical superlattices” can be used to controllably place, guide, and manipulate these solitons. In particular, we use numerical experiments to displace solitons by turning on a secondary lattice structure, transfer solitons from one location to another by shifting one superlattice substructure relative to the other, and implement solitonic “path-following”, in which a matter wave follows the time-dependent lattice substructure into oscillatory motion.

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