Coherent control of exciton–biexciton beats: direction selectivity of four‐wave‐mixing signals in experiment and microscopic theory

Abstract

PACS 42.65. Ky, 78.67.De In experiments and simulations based on a microscopic theory the optical coherent control of excitonbiexciton beats in coherent four-wave-mixing signals from a semiconductor quantum well is demonstrated. It is found that a reduction of the beat amplitude for one four-wave-mixing direction may at the same time coincide with a large beat amplitude for the other direction. The results can be understood by considering that at least two-photon processes are required to coherently excite biexcitonic transitions which are responsible for the occurrence of the beat structure in the four-wave-mixing signals.