AharonovBohm ballistic billiards
Abstract
The measured orbital susceptibility of an array of 10 ^{5}isolated GaAs squares of area L^{2} = 4.5 × 4.5 μm ^{2} has a paramagnetic contribution ≈ k_{F}L = 100 times larger than the Landau susceptibility. With increasing magnetic field, this paramagnetic susceptibility decreases on a field scale of order H_{0} ≈ φ_{0}/ L^{2}, where φ_{0} = h/ e is the flux quantum. As the temperature is raised, this orbital paramagnetism decreases on the scale of 0.5 K ≈ E_{c}/2 where E_{c} = hv_{F}/ L is the correlation energy. These experimental findings can be checked using Coulomb blockade spectroscopy. To this end, the thermodynamic relations between chemical potential and orbital currents are derived.
 Publication:

Physica B Condensed Matter
 Pub Date:
 June 1993
 DOI:
 10.1016/09214526(93)90161X
 Bibcode:
 1993PhyB..189..204L