Cloud shape of a molecular Bose-Einstein condensate in a disordered trap: A case study of the dirty boson problem

Nagler B, Radonjic M, Barbosa S, Koch J, Pelster A, Widera A (2020)


Publication Type: Journal article

Publication year: 2020

Journal

Book Volume: 22

Article Number: 033021

Journal Issue: 3

DOI: 10.1088/1367-2630/ab73cb

Abstract

We investigate, both experimentally and theoretically, the static geometric properties of a harmonically trapped Bose-Einstein condensate of 6Li2 molecules in laser speckle potentials. Experimentally, we measure the in situ column density profiles and the corresponding transverse cloud widths over many laser speckle realizations. We compare the measured widths with a theory that is non-perturbative with respect to the disorder and includes quantum fluctuations. Importantly, for small disorder strengths we find quantitative agreement with the perturbative approach of Huang and Meng, which is based on Bogoliubov theory. For strong disorder our theory perfectly reproduces the geometric mean of the measured transverse widths. However, we also observe a systematic deviation of the individual measured widths from the theoretically predicted ones. In fact, the measured cloud aspect ratio monotonously decreases with increasing disorder strength, while the theory yields a constant ratio. We attribute this discrepancy to the utilized local density approximation, whose possible failure for strong disorder suggests a potential future improvement.

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How to cite

APA:

Nagler, B., Radonjic, M., Barbosa, S., Koch, J., Pelster, A., & Widera, A. (2020). Cloud shape of a molecular Bose-Einstein condensate in a disordered trap: A case study of the dirty boson problem. New Journal of Physics, 22(3). https://dx.doi.org/10.1088/1367-2630/ab73cb

MLA:

Nagler, Benjamin, et al. "Cloud shape of a molecular Bose-Einstein condensate in a disordered trap: A case study of the dirty boson problem." New Journal of Physics 22.3 (2020).

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