Flux Lattices Reformulated

Published

December 12, 2012

Author(s)

Ian B. Spielman, Gediminas Juzeliunas

Abstract

We theoretically explore the optical flux lattices produced for ultra-cold atoms subject to laser fields where both the atom-light coupling and the effective detuning are spatially periodic. We analyze the geometric vector potential and the magnetic flux it generates, as well as the accompanying geometric scalar potential. We show how to understand the gauge-dependent Aharonov-Bohm singularities in the vector potential, and calculate the continuous magnetic flux through the elementary cell in terms of these singularities. The analysis is illustrated with a square optical flux lattice. We conclude with an explicit laser configuration yielding such a lattice using a set of five properly chosen beams with two counterpropagating pairs (one along the x axes and the other y axes), together with a single beam along the z axis. We show that this lattice is not phase-stable, and identify the one phase-difference that affects the magnetic flux. Thus armed with realistic laser setup, we directly compute the Chern number of the lowest Bloch band to identify the region where the non-zero magnetic flux produces a topologically non-trivial band structure.

Citation

New Journal of Physics

Pub Type

Journals

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Keywords

artificial gauge fields, spin orbit coupling, topological insulators, ultracold atoms

Citation

Spielman, I. and Juzeliunas, G. (2012), Flux Lattices Reformulated, New Journal of Physics, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=911751 (Accessed April 24, 2024)