  Electrons are the carriers of heat and electricity in materials, and exhibit
abundant transport phenomena such as ballistic, diffusive, and hydrodynamic
behaviors in systems with different sizes. The electron Boltzmann transport
equation (eBTE) is a reliable model for describing electron transport, but it
is a challenging problem to efficiently obtain the numerical solutions of eBTE
within one unified scheme involving ballistic, hydrodynamics and/or diffusive
regimes. In this work, a discrete unified gas kinetic scheme (DUGKS) in
finite-volume framework is developed based on the eBTE with the Callaway
relaxation model for electron transport. By reconstructing the distribution
function at the cell interface, the processes of electron drift and scattering
are coupled together within a single time step. Numerical tests demonstrate
that the DUGKS can be adaptively applied to multiscale electron transport,
across different regimes.
