Exciton Confinement in Traps Formed by a Laterally Modulated Gate Voltage

In semiconductor materials, cold gases of bosons can be realized in the system of indirect excitons in coupled quantum well structures. Boson confinement in potential traps improves the critical temperature for Bose-Einstein condensation and allows manipulation of the bosons by varying the trap potential [1,2]. Here, we present in-plane potential traps for indirect excitons, where the traps are formed by a laterally modulated gate voltage. The calculated trap design allows effective exciton confinement as well as in situ manipulation of excitons by the gate electrodes that control the confining potential. The design also ensures that the electric fields caused by the confining potential are well below the threshold for the exciton dissociation. Experiments with indirect excitons in the traps are presented as well. 1. E.A. Cornell, C.E. Wieman, Rev. Mod. Phys. 74, 875 (2002). 2. W. Ketterle, Rev. Mod. Phys. 74, 1131 (2002).