Single electron transport in quantum devices

Klaus Ensslin (ETH Zurich)

Semiconductor quantum devices have reached a precision and mautrity that the flow of electrons, i.e. the electrical current, can be measured in a time-resolved way, one electron after the other. This allows to measure ultra small currents, current correlations and quantum shot noise. The coupling between quantum devices can be strong and  fundamental relations of classical thermodynamics can be probed, such as the second law of thermodynmaics on the level of individual electrons.

Furthermore single electron charge detection in AlGaAs/GaAs heterostructures allows for a precise determination of the tunneling rates into and out of the quantum dot. This leads to a measurement of the level degeneracy of a state, which depends on its occulation and it can be changed by magnetic fields. In addition show that charge fluctuations in and out of equilibrium can be measured by implementing feedback loops into the detection setup. For double dots with a well-defined orientation of electron tunneling the strength of spin-orbit interaction can be investigated and tuned on the level of individual electrons.

The talk will proceed by presenting basic properties of electron transport through quantum devices on a basic level.