New many-body mechanism of intraband carrier relaxation in quantum dots embedded in doped heterostructures

The role of longitudinal surface collective excitations of doped elements of heterostructure in electronic dynamics of quantum dots was studied theoretically. A new mechanism of intraband quantum dot carrier relaxation is proposed where an interaction between the quantum dot carriers and electric potential induced by charge density fluctuations in the element with frequencies of the surface plasmon–LO–phonon modes is responsible for the process. It has been found that two branches of the surface plasmon–LO–phonon modes of the doped element are effectively involved in the relaxation even in the case when a distance between the element and the quantum dots is relatively long (50÷150 nm). The calculations show that relaxation rates about 1012 s−1 are expected at the distance of 100 nm rising by an order of magnitude at a distance of 30 nm.