Final Defense

Yang Gao, UT-Austin

"Two applications of semiclassical theory: Landau level quantization and longitudinal magneto-conductivity"

10:00am, RLM 11.204

Abstract: In this talk, I will demonstrate that the Onsager's rule for Landau levels can be generalized as a power series expansion of magnetic field, with corresponding coefficients being zero-field magnetic response functions. I will discuss the experimental and physical significance of this generalization of Onsager's rule. I will also derive a novel contribution to the current when electric field is parallel to magnetic field based on the semiclassical theory. I find that the B-dependent part of the corresponding conductivity is typically non-trivial and does not require a special Fermi surface. Although this part of conductivity usually has indefinite signs, it contains a contribution that is always positive and can thus provide a mechanism for the positive magneto-conductivity in the semiclassical transport regime.