QUANTUM TRANSPORT IN BALLISTIC NANO-SCALE CORBINO DISKS

A theoretical study is presented of transport through ballistic nano-scale Corbino disks with ideal contacts. Quantum, classical and semi-classical results are compared. At magnetic field B = 0 and low temperatures, the conductance G is quantized in odd integer multiples of 2e2/h. G is not a monotonic function of B, because conduction via successive quantum states switches on and off as B increases. G shows an approximate plateau at low B (for r(c) > (r(i) + r(o))/2) and is zero at high B, for r(c) < (r(o) - r(i))/2. r(c) is the cyclotron radius. r(i) and r(o) are the radii of the inner and outer contacts. In between, G falls approximately linearly with B, modulated by structures on the scale of e2 / h due to conduction through individual quantum states.