International Journal of Modern Physics B
Collective Mode of Semion Systems
X. C. Xie, Song He, S. Das Sarma
Abstract
The ground and the excited states of a two-dimensional anyon system are studied via finite-size numerical calculations and single-mode approximation in a spherical geometry. It is shown that Laughlin's mean field theory gives an accurate description of the ground state properties. We find, consistent with earlier analytic theories, that the collective mode of the system exhibits a linear dispersion in the long wavelength limit, and predict a novel roton minimum at a finite value of the wavenumber q. We also discuss the consequences on the anyon spectrum of having a model repulsive interaction between the particles.