Localisation of weakly interacting bosons in two dimensions: disorder vs lattice geometry effects
| Autor: | Luis A. Gonzalez-Garcia, Rosario Paredes, Santiago F. Caballero-Benitez |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2019 |
| Předmět: |
0301 basic medicine
Quantum fluid Atomic Physics (physics.atom-ph) Quantum fluids and solids Coordination number lcsh:Medicine FOS: Physical sciences Geometry Condensed Matter::Disordered Systems and Neural Networks Article Physics - Atomic Physics 03 medical and health sciences 0302 clinical medicine Lattice (order) lcsh:Science Quantum tunnelling Boson Physics Optical lattice Quantum Physics Multidisciplinary lcsh:R Bose-Einstein condensates 030104 developmental biology Amplitude Quantum Gases (cond-mat.quant-gas) lcsh:Q Quantum simulation Ground state Quantum Physics (quant-ph) Condensed Matter - Quantum Gases 030217 neurology & neurosurgery |
| Zdroj: | Scientific Reports Scientific Reports, Vol 9, Iss 1, Pp 1-12 (2019) |
| ISSN: | 2045-2322 |
| Popis: | We investigate the effects of disorder and lattice geometry against localisation phenomena in a weakly interacting ultracold bosonic gas confined in a 2D optical lattice. The behaviour of the quantum fluid is studied at the mean-field level performing computational experiments, as a function of disorder strength for lattices of sizes similar to current experiments. Quantification of localisation, away from the Bose glass phase, was obtained directly from the stationary density profiles through a robust statistical analysis of the condensate component, as a function of the disorder amplitude. Our results show a smooth transition, or crossover, to localisation induced by disorder in square and triangular lattices. In contrast, associated to its larger tunneling amplitude, honeycomb lattices show absence of localisation for the same range of disorder strengths and same lattice amplitude, while also exhibiting partial localisation for large disorder amplitudes. We also conclude that the coordination number z have a partial influence on how fast this smooth transition occurs as the system size increases. Signatures of disorder are also found in the ground state energy spectrum, where a continuous distribution emerges instead of a distribution of sharp peaks proper to the system in the absence of disorder. 13 pages, 6 Figures (Final Accepted version) |
| Databáze: | OpenAIRE |
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