Giant many-body enhancement of low temperature thermal-electron–acoustic-phonon coupling in semiconductor quantum wires

We show that in a semiconductor quantum wire the energy relaxation of the excited one-dimensional electron gas due to acoustic phonon emission is strongly enhanced at low temperatures by a subtle many-body effect arising from the broadening caused by the electron–acoustic-phonon interaction. This broadening opens up a ‘‘virtual’’ channel for energy transfer from the electrons to the low energy tail of the phonon spectral function. This peculiarly one-dimensional many-body effect causes a very large enhancement of the power loss over the bare value and restores the Bloch-Grüneisen power law temperature dependence of the energy loss rate at low temperatures.