Title: GPUQT: An efficient linear-scaling quantum transport code fully implemented on graphics processing units,
Abstract: We present GPUQT, a quantum transport code fully implemented on graphics
processing units. Using this code, one can obtain intrinsic electronic
transport properties of large systems described by a real-space tight-binding
Hamiltonian together with one or more types of disorder. The DC Kubo
conductivity is represented as a time integral of the velocity auto-correlation
or a time derivative of the mean square displacement. Linear scaling (with
respect to the total number of orbitals in the system) computation time and
memory usage are achieved by using various numerical techniques, including
sparse matrix-vector multiplication, random phase approximation of trace,
Chebyshev expansion of quantum evolution operator, and kernel polynomial method
for quantum resolution operator. We describe the inputs and outputs of GPUQT
and give two examples to demonstrate its usage, paying attention to the
interpretations of the results.