Oscillation modes of two-dimensional nanostructures within the time-dependent local-spin-density approximation

TL;DR

This paper uses the time-dependent local-spin-density approximation to analyze spin-density oscillations and predict new soft spin-twist excitation modes in two-dimensional nanostructures, especially quantum dots.

Contribution

It introduces a novel application of the time-dependent local-spin-density approximation to 2D nanostructures and predicts a new class of low-energy spin-twist modes.

Findings

Identification of spin-density oscillations in 2D nanostructures.

Prediction of soft spin-twist modes with energies below spin dipole oscillations.

Analysis of the impact of spin-density waves on excitation spectra.

Abstract

We apply the time-dependent local-spin-density approximation as general theory to describe ground states and spin-density oscillations in the linear response regime of two-dimensional nanostructures of arbitrary shape. For this purpose, a frequency analysis of the simulated real-time evolution is performed. The effect on the response of the recently proposed spin-density waves in the ground state of certain parabolic quantum dots is considered. They lead to the prediction of a new class of excitations, soft spin-twist modes, with energies well below that of the spin dipole oscillation.