The Role of Spin in Some Fractional Quantum Hall Ground States
Speaker: Simon Davenport, Oxford University
Department: Electrical Engineering
Location: Engineering Quadrangle B418
Date/Time: Monday, March 25, 2013, 4:00 p.m. - 5:00 p.m.
In this talk we shall discuss multi-component fractional quantum Hall (FQH) physics occurring in systems with spin and/or valley degrees of freedom. In our discussion we shall focus on the physics of "spin-transitions" between different FQH states having different net spin polarizations as a function of the ratio of Zeeman to Coulomb energy. We will present some predictions of composite fermion theory for spin transitions in the LLL at filling factors 2/3, 3/5 and 4/7 and in 2nd LL at filling fractions 8/3, 13/5 and 18/7, the 8/3 case, being the subject of recent experiments. Time permitting, we shall briefly discuss analogous valley-transitions found in AlAs and spin-transitions observed in suspended Graphene and we shall reflect on the possibilities of realizing non-abelian phases in multi-component quantum Hall systems.