Description
Introduction to selected phenomena of quantum transport
Electric conductivity - a prime example of a transport phenomenon - can be described classically in many cases. Electrons are thought of as point-like particles with definite velocity, accelerated by electric field which carry electric current. Quantum-mechanical view where electrons are considered waves is often leading to practically the same conclusions as the classical one. This course deals with a subjectively selected group of phenomena where the two pictures differ and genuine consequences of quantum mechanics become apparent. For example, the measured transversal resistivity in the Quantum Hall Effect exhibits steps quantized in the units of h/e^2 whereas it is strictly linear (without steps) in the applied magnetic field in its classical version. Given that the quantum mechanics describes microscopical objects (such as individual atoms), it is no surprise that many of these phenomena occur in devices with nanometre size and/or reduced dimensionality.
Syllabus: (1) Classical vs quantum transport. Basics of quantum mechanics. Heterostructures. (2) Conductance and thermopower quantisation in 1D. Tunneling through a quantum dot. (3) Aharonov-Bohm effect. Quantum Hall Effects. (4) Spintronics at nanoscale: magnetic tunneling junctions,
spin-orbit torques and ferromagnetic resonance.
