Quantum coherent negative bend resistance in InSb mesoscopic structures

Transport measurements were made on four-terminal devices fabricated from InSb/Al_xIn_(1-x)Sb quantum well structures at temperatures from 1.5 to 300K. Negative bend resistance, which is characteristic of ballistic transport, was observed in devices of channel widths 0.2 or 0.5 {\mu}m. We have improved upon the existing implementations of R-matrix theory in device physics by introducing boundary conditions that dramatically speed convergence. By comparison with R-matrix calculations, we show that the experimental observations are consistent with quantum coherent transport.