Multipole excitations in quantum dots

TL;DR

This paper uses time-dependent local-spin density theory to analyze multipole excitations in quantum dots, matching experimental observations and revealing the origins of high multipolarity edge modes.

Contribution

It provides a theoretical analysis of multipole excitations in quantum dots, clarifying the nature and origin of observed modes and their angular momentum.

Findings

Good agreement between theory and experiment.

High multipolarity spin edge modes originate from interband transitions.

Identified angular momentum of observed modes.

Abstract

We have employed time-dependent local-spin density theory to analyze the multipole spin and charge density excitations recently found in GaAs-AlGaAs quatum dots [C. Sch\"uller et al, Phys. Rev. Lett {\bf 80}, 2673 (1998)]. The overall agreement between theory and experiment is good, identifying the angular momentum of the modes observed in the experiment. We have found that high multipolarity spin density edge modes originate from interband transitions instead that from intraband transitions, as it happens in the dipole case.