From Anderson to anomalous localization in cold atomic gases with effective spin-orbit coupling

M. J. Edmonds; J. Otterbach; R. G. Unanyan; M. Fleischhauer; M. Titov; P. Ohberg

doi:10.1088/1367-2630/14/7/073056

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arXiv · 1106.5925

From Anderson to anomalous localization in cold atomic gases with effective spin-orbit coupling

M. J. Edmonds·J. Otterbach·R. G. Unanyan·M. Fleischhauer·M. Titov·P. Ohberg

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Abstract

We study the dynamics of a one-dimensional spin-orbit coupled Schrodinger particle with two internal components moving in a random potential. We show that this model can be implemented by the interaction of cold atoms with external lasers and additional Zeeman and Stark shifts. By direct numerical simulations a crossover from an exponential Anderson-type localization to an anomalous power-law behavior of the intensity correlation is found when the spin-orbit coupling becomes large. The power-law behavior is connected to a Dyson singularity in the density of states emerging at zero energy when the system approaches the quasi-relativistic limit of the random mass Dirac model. We discuss conditions under which the crossover is observable in an experiment with ultracold atoms and construct explicitly the zero-energy state, thus proving its existence under proper conditions.

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BibTeX RIS

M. J. Edmonds, J. Otterbach, R. G. Unanyan, M. Fleischhauer, M. Titov, P. Ohberg. 2012-02-23. From Anderson to anomalous localization in cold atomic gases with effective spin-orbit coupling. https://doi.org/10.1088/1367-2630%2F14%2F7%2F073056

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