Dimensional Reduction and Localization of a Bose-Einstein Condensate in a Quasi-1D Bichromatic Optical Lattice

L. Salasnicha,b and S.K. Adhikari c aDipartimento di Fisica "Galileo Galilei" and CNISM, Università di Padova, Via Marzolo 8, 35131 Padova, Italy bIstituto Nazionale di Ottica (INO) del Consiglio Nazionale delle Ricerche (CNR), Sezione di Sesto Fiorentino, Via Nello Carrara, 1 - 50019 Sesto Fiorentino, Italy 3Instituto de Fisica Teorica, Universidade Estadual Paulista, UNESP 01.140-070 Sao Paulo, Sao Paulo, Brazil

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We analyze the localization of a Bose-Einstein condensate in a one-dimensional bichromatic quasi-periodic optical-lattice potential by numerically solving the 1D Gross-Pitaevskii equation (1D GPE). We first derive the 1D Gross-Pitaevskii equation from the dimensional reduction of the 3D quantum field theory of interacting bosons obtaining two coupled differential equations (for axial wave fuction and space-time dependent transverse width) which reduce to the 1D Gross-Pitaevskii equation under strict conditions. Then, by using the 1D Gross-Pitaevskii equation we report the suppression of localization in the interacting Bose-Einstein condensate when the repulsive scattering length between bosonic atoms is sufficiently large.

DOI: 10.12693/APhysPolA.128.979 PACS numbers: 03.75.Nt, 03.75.Lm, 64.60.Cn, 67.85.Hj