Magnetoroton scattering by phonons in fractional quantum Hall liquids - art. no. 235304

Motivated by recent phonon-spectroscopy experiments in the fractional quant um Hall regime we consider processes in which thermally excited magnetoroto n excitations are scattered by low-energy phonons. We show that such scatte ring processes can never give rise to dissociation of magnetorotons into un bound charged quasiparticles as had been proposed previously. In addition, we show that scattering of magnetorotons to longer wavelengths by phonon ab sorption is possible because of the shape of the magnetoroton-dispersion cu rve and it is shown that there is a characteristic cross-over temperature a bove which the rate of energy transfer to the electron gas changes from an exponential (activated) Co a power-law dependence on the effective phonon t emperature.