Para- and Ortho-Trions on a Ring: A Simple Model

Abstract

Motivated by recent experiments on luminescence from semiconductor nanorings, we study theoretically the quantized states of a charged exciton (trion) in a ring geometry. In particular, we compare the energies of the states with antiparallel (para-trion) and parallel (ortho-trion) spin configurations of two electrons, that, together with a hole, constitute a trion. In order to assess the experimentally relevant domain of parameters, when the size quantization energy is comparable to the exciton binding energy, we adopt a simple model of an infinitely narrow ring and short-range electron–electron and electron–hole interactions.