2001/06/21 by M. A. Baranov, М. А. Баранов, I. S. Burmistrov +1
Physics and Astronomy · #Physics of Superconductivity and Magnetism #Quantum and electron transport phenomena #Topological Materials and Phenomena #cond-mat.mes-hall
paper · pdf · doi:10.1103/physrevb.66.075317
published as Phys. Rev. B66, 075317 (2002) · 19 pages, 3 tables and one figure
arxiv created 2001/06/21 · openalex publication_date 2002/08/09 · arxiv updated 2009/11/30 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28
We consider the Finkelstein action describing a system of spin-polarized or spinless electrons in 2+2\ensuremathε dimensions, in the presence of disorder as well as the Coulomb interactions. We extend the renormalization-group analysis of our previous work and evaluate the metal-insulator transition of the electron gas to second order in an \ensuremathε expansion. We obtain the complete scaling behavior of physical observables like the conductivity and the specific heat with varying frequency, temperature, and/or electron density. We extend the results for the interacting electron gas in 2+2\ensuremathε dimensions to include the quantum critical behavior of the plateau transitions in the quantum Hall regime. Although these transitions have a very different microscopic origin and are controlled by a topological term in the action (\ensuremathθ term), the quantum critical behavior is in many ways the same in both cases. We show that the two independent critical exponents of the quantum Hall plateau transitions, previously denoted as \ensuremathν and p, control not only the scaling behavior of the conductances \ensuremathσxx and \ensuremathσxy at finite temperatures T, but also the non-Fermi-liquid behavior of the specific heat (cv\ensuremath∝Tp). To extract the numerical values of \ensuremathν and p it is necessary to extend the experiments on transport to include the specific heat of the electron gas.