New collective modes in wide quantum wells with in-plane magnetic fields

Abstract

We theoretically investigate, within the random phase approximation, the collective excitations of symmetric wide quantum wells under in-plane magnetic fields B || . We find that the B || field significantly affects the frequencies, (an-)isotropy and types of the plasmon modes. In particular, a high B || can induce an additional branch of undamped acoustic-like plasmons, which does not exist in single quantum wells without B || .