Tunneling in Nanoscale Devices

Theoretical treatments of tunneling in electronic devices are often based on one-dimensional (1D) approximations. Here we show that for many nanoscale devices, such as widely studied semiconductor gate-defined quantum dots, 1D approximations yield an incorrect functional dependence on the tunneling parameters (e.g., lead width and barrier length) and an incorrect magnitude for the transport conductance. Remarkably, the physics of tunneling in 2D or 3D also yields transport behavior that appears classical (like Ohm's law), even deep in the quantum regime.