Classical electromagnetism is linear, however strong fields varying slowly at the electron rest energy scale, polarize the quantum vacuum and give rise to nonlinear phenomena, such as scattering or splitting of photons and birefringence. These effects become relevant only in very strong fields that exist in exotic environments e.g. in the vicinity of heavy nuclei or neutron stars.
We show that, analogous nonlinear effects arise in Dirac matter at a field strength of ~1 T. The resulting field dependent electronic contribution to the electric/magnetic susceptibility tensor of Dirac matter is anisotropic and arbitrarily large. We find universal expressions for susceptibilities including the effect of crystal anisotropy and present applications to recently discovered materials.
About the presenter
Dr Aydin C. Keser is a theoretical postdoctoral researcher working with Dr Dimitrie Culcer at UNSW on transport properties of surface states in topological materials, including disorder and interaction effects. Dr Keser completed his master’s and PhD in the University of Maryland as a Fulbright visiting scholar and he is a member of the American Physical Society. He is currently working on non-universal corrections to transport due to interactions between carriers, as part of FLEET’s Research Theme 1, topological materials.