In lateral quantum dots, the combined effect of both Dresselhaus and Bychkov-Rashba spin-orbit coupling is equivalent to an effective magnetic field ±BSO which has the opposite sign for sz=±1/2 spin electrons. When the external magnetic field is perpendicular to the planar structure, the field BSO generates an additional splitting for electron states as compared to the spin splitting in the in-plane field orientation. The anisotropy of spin splitting has been measured and then analyzed in terms of spin-orbit coupling in several AlGaAs/GaAs quantum dots by means of resonant tunneling spectroscopy. From the measured values and sign of the anisotropy we are able to determine the dominating spin-orbit coupling mechanism.
Altshuler and Falko predicted that spin-orbit coupling in lateral quantum dots leads to an effective magnetic field acting oppositely on spin up/down electrons. The resulting difference between the spin splitting for dots in a perpendicular and in-plane magnetic field has been observed experimentally by the Hannover group. RAE_import_type : Journal article RAE_uoa_type : Physics