Portal de Periódicos da CAPES

Double quantum dot in a quantum dash: Optical properties

2013; American Institute of Physics; Volume: 114; Issue: 18 Linguagem: Inglês

10.1063/1.4829700

1520-8850

Piotr Kaczmarkiewicz, Paweł Machnikowski, T. Kühn,

Quantum and electron transport phenomena

We study the optical properties of highly elongated, highly flattened quantum dot structures, also referred to as quantum dashes, characterized by the presence of two trapping centers located along the structure. Such a system can exhibit some of the properties characteristic for double quantum dots. We show that sub- and super-radiant states can form for certain quantum dash geometries, which is manifested by a pronounced transfer of intensity between spectral lines, accompanied by the appearance of strong electron-hole correlations. We also compare exciton absorption spectra and polarization properties of a system with a single and double trapping center and show how the geometry of multiple trapping centers influences the optical properties of the system. We show that for a broad range of trapping geometries the relative absorption intensity of the ground state is larger than that of the lowest excited states, contrary to the quantum dash systems characterized by a single trapping center. Thus, optical properties of these structures are determined by fine details of their morphology.