1 / 2

Striking similarity between the apparent magnetic field-induced semimetal-insulator

Field-induced mass of Dirac fermion excitations in carbon-based materials Dmitri Khveshchenko, University of North Carolina at Chapel Hill , DMR 0349881.

calvin-roach
Download Presentation

Striking similarity between the apparent magnetic field-induced semimetal-insulator

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Field-induced mass of Dirac fermion excitations in carbon-based materialsDmitri Khveshchenko, University of North Carolina at Chapel Hill , DMR 0349881 • The goal of this project is to develop new and advance the existing theoretical and computational tools for analyzing the non-Fermi-liquid properties of and emergent behaviors in strongly correlated electron systems characterized by the presence of Dirac-like excitations near isolated Fermi points and singular interactions, including graphene, pyrolitic graphite, superconducting high-Tc cuprates, etc. • In the last year, it has been realized that, despite an order of magnitude difference in the scales of the corresponding critical magnetic fields, graphene and layered graphite might both feature the same phenomenon of “magnetic catalysis” which endows the gapless Dirac fermions in these systems with a field-induced mass. Striking similarity between the apparent magnetic field-induced semimetal-insulator transitions in highly oriented pyrolitic graphite (left, data by Y.Kopelevich et al, ‘00) and graphene (right, data by N.P.Ong’s group, ‘07). From top to bottom: resistivity (conductivity) as a function of temperature, field-dependent scaling, and field-induced Dirac fermion mass.

  2. Field-induced mass of Dirac fermion excitations in carbon-based materialsDmitri Khveshchenko, University of North Carolina at Chapel Hill , DMR 0349881 • This research establishes a new connection between some novel behaviors in carbon-based materials and the phenomena that have been previously discussed in the context of abstract quantum field theory (chiral symmetry breaking, magnetic catalysis, etc.): namely, the behavior of electrons in these materials might be reminiscent to that in relativistic Quantum Electrodynamics beyond the mere kinematical level, as found in the earlier work. • This project is also expected to have a strong educational component and achieve a broader impact through the recruitment and individual training of students and postdocs with the focus on combining theoretical research of a broad range of interdisciplinary topics with potential device applications. Magnetic field-induced gapping of the Dirac K-point is analogous to the phenomenon of chiral symmetry breaking in QED_3 (T.Appelquist et al, ’88).

More Related