Effective preparation and collisional decay of atomic condensates in excited bands of an optical lattice

摘要: We present a method for the effective preparation of Bose-Einstein condensate (BEC) into excited bands an optical lattice via standing-wave pulse sequence. With our method, BEC can be prepared in either single Bloch state band or coherent superposition states different bands. Our scheme is experimentally demonstrated by preparing ${}^{87}$Rb $d$ and $s$- $d$-band one-dimensional lattice, within few tens microseconds. further measure decay carry analytical calculation collisional atoms excited-band states. theoretical experimental results agree well.