  The transfer of heat between electrons and phonons plays a key role for
thermal management in future nanowire-based devices, but only a few
experimental measurements of electron-phonon (e-ph) coupling in nanowires are
available. Here, we combine experimental temperature measurements on an
InAs/InP heterostructure nanowire system with finite element modeling (FEM) to
extract information on heat flow mediated by e-ph coupling. We find that the
electron and phonon temperatures in our system are highly coupled even at
temperatures as low as 2 K. Additionally, we find evidence that the usual
power-law temperature dependence of electron-phonon coupling may not correctly
describe the coupling in nanowires and show that this result is consistent with
previous research on similar one-dimensional electron systems. We also compare
the strength of the observed e-ph coupling to a theoretical analysis of e-ph
interaction in InAs nanowires, which predicts a significantly weaker coupling
strength than observed experimentally.
