The impact of low symmetry on the electronic and optical properties of quantum wires

Abstract

The role of the confinement potential symmetry on the electronic and optical properties of quantum wires is systematically studied. In a wide class of quantum wires with mirror symmetry we evidence a new set of optical transitions resulting both from band mixing and C2v symmetry breaking at zone center. Several kinds of quasi-one-dimensional excitons are predicted as well as their specific dipole coupling. Even for ultralow C1 symmetry we find independent excitons with distinct polarization selection rules.

Coherence retention by resonance dynamic dipole–dipole interaction among quantum dot ensemble for quantum computing

“…the change in angular momentum m during the electronic transition should be equal to the helicity of the photon absorbed or emitted. This type of parity relation has already been discussed in experiments as well as in theory [13]. In the case of quantum well and circularly …”

Optical injection of charge current in quantum wires: Oscillations induced by excitonic effects

“…As a consequence, all optically active excitons exhibit the zone center symmetry and can be labelled by the irreps of the point group of the QWR. 10 Furthermore, excitons being product states of two particles with half-integer spin, their total spin is an integer. By contrast to the single particle case, excitons therefore belong to the irreps of the single group.…”

“…By contrast to the single particle case, excitons therefore belong to the irreps of the single group. 10 In QWRs with C 2v symmetry, the optically active excitons can consequently be classified according to the four onedimensional irreps denoted by A 1 , B 1 , A 2 , and B 2 ͑notations of Ref. 15͒.…”

Consequences of Low Symmetry in Quantum Wires: Exciton Degeneracies and Quasi-Equilibrium High-Density Regime

“…Introduction The influence of both heterostructure spatial symmetry and time-reversal (TR) symmetry was recently used to provide stringent conditions for the construction of excitons in quantum wires (QWR) with well-defined selection rules [1,2], despite the fact that the symmetry is usually quite low. It was discovered long ago by the pioneers of quantum mechanics that the interplay between symmetry and quantum mechanics leads to results that are not obvious from a classical intuition [2].…”

“…It was discovered long ago by the pioneers of quantum mechanics that the interplay between symmetry and quantum mechanics leads to results that are not obvious from a classical intuition [2]. In addition the use of group theory is today unavoidable, to find all the symmetry-induced properties both systematically and in a quicker way, and to get a standard notation to classify the symmetry of the objects [3,4] 1 .…”