DISSIPATIVE QUANTUM TUNNELING AND MAGNETIC RESPONSE OF A SINGLE-ELECTRON IN A 4-WELL POTENTIAL

We study dissipative tunneling of a single electron in a four-well sem iconductor nanostructure threaded by a magnetic flux. The system under consideration allows us to investigate an influence of dissipation an d irreversibility on two fundamental quantum-interference phenomena: t unneling and the Aharonov-Bohm effect at once. We calculate the steady -state magnetic moment of the particle (orbital paramagnetism) and stu dy its temperature dependence. The existence of orbital paramagnetism is evidence for electron persistent tunneling between quantum dots as well as for the conservation of quantum coherence in the thermodynamic -equilibrium state. (C) 1998 Academic Press.