B\"uttiker probes for dissipative phonon quantum transport in semiconductor nanostructures

Theoretical prediction of phonon transport in modern semiconductor nanodevices requires atomic resolution of device features and quantum transport models covering coherent and incoherent effects. The nonequilibrium Green's function method (NEGF) is known to serve this purpose very well, but is numerically very expensive. This work extends the very efficient B\"uttiker probe concept to phonon NEGF and discusses all implications of this method. B\"uttiker probe parameters are presented that reproduce within NEGF experimental phonon conductances of Si and Ge between 10K and 1000K. Results of this method in SiGe heterojunctions illustrate the impact of interface relaxation on the device heat conductance and the importance of inelastic scattering for the phonon distribution.