ELFT HÍRADÓ

[Szeminárium koordinátor <szfi-seminar AT wigner.mta.hu>]

WIGNER SZFI Seminar

Universal Scaling Theory of the Boundary Geometric Tensor in Disordered Metals

Werner Miklós
Wigner RCP SZFI

Tuesday, 19 March 2019 10:00, KFKI Campus, Bldg. 1, 2nd floor, Conference Room

We study the Anderson metal-insulator transition of spinless fermions in a three dimensional disordered lattice in weak magnetic fields. We show that the one-parameter scaling theory of localization loses its vailidity in weak random magnetic fields: we find a two-parameter renormalization group flow instead that describes the crossover between the critical points of the orthogonal and unitary universality classes. The scaling variables are provided by the boundary quantum geometric tensor that measures the sensitivity of eigenstates on the boundary conditions. In the flow generated by the finite size scaling of the quantum geometric tensor one can easily identify the critical points and also determine the critical exponents. Critical distributions of the quantum geometric tensor are universal and exhibit a remarkable isotropy even in a homogeneous magnetic field. Based on the analytic relation between the quantum geometric tensor and the T=0 DC Hall conductance of the system we predict universal and isotropic Hall conductance fluctuations at the metal-insulator transition in an external magnetic field.

 

Everyone is welcome to attend.

János Asbóth
szfi-seminar AT wigner.mta.hu