Calculation of Drag and Superfluid Velocity from the Microscopic Parameters and Excitation Energies of a Two-Component Bose-Einstein Condensate on an Optical Lattice - Condensed Matter > Quantum GasesReport as inadecuate




Calculation of Drag and Superfluid Velocity from the Microscopic Parameters and Excitation Energies of a Two-Component Bose-Einstein Condensate on an Optical Lattice - Condensed Matter > Quantum Gases - Download this document for free, or read online. Document in PDF available to download.

Abstract: We investigate a model of a two-component Bose-Einstein condensate residingon an optical lattice. Within a Bogolioubov-approach at the mean-field level,we derive exact analytical expressions for the excitation spectrum of thetwo-component condensate when taking into account hopping and interactionsbetween arbitrary sites. Our results thus constitute a basis for works thatseek to clarify the effects of higher-order interactions in the system. Weinvestigate the excitation spectrum and the two branches of superfluid velocityin more detail for two limiting cases of particular relevance. Moreover, werelate the hopping and interaction parameters in the effective Bose-Hubbardmodel to microscopic parameters in the system, such as the laserlightwavelength and atomic masses of the components in the condensate. These resultsare then used to calculate analytically and numerically the drag coefficientbetween the components of the condensate. We find that the drag is mosteffective close to the symmetric case of equal masses between the components,regardless of the strength of the intercomponent interaction and the latticewell depth.



Author: Jacob Linder, Asle Sudbø

Source: https://arxiv.org/







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