Negative-mass effects in spin-orbit coupled Bose-Einstein condensates
Abstract
Negative effective masses can be realised by engineering the dispersion relation in a variety of quantum systems. A recent experiment with spin-orbit coupled Bose-Einstein condensates has shown that a negative effective mass can halt the free expansion of the condensate and produce fringes in the density [M. Khamehchi et al., Phys. Rev. Lett. 118, 155301 (2017)]. Here, we show that the observed fringes are due to the negativity of only one of the two effective mass parameters that characterise the dispersion, which leads to previously predicted self-interference of the wave packet. We show how confgurations are nevertheless accessible to spin-orbit coupled Bose-Einstein condensates where both mass parameters controlling the propagation and diffusion of the condensate are negative, resulting in the novel phenomenon of counter-propagating self-interfering packets.
Cite
@article{arxiv.1801.04779,
title = {Negative-mass effects in spin-orbit coupled Bose-Einstein condensates},
author = {David Colas and Fabrice P. Laussy and Matthew J. Davis},
journal= {arXiv preprint arXiv:1801.04779},
year = {2018}
}