Interaction and Correlation Effects in Quasi Two-dimensional Materials

COFFEE_KLATCH  · Invited

Abstract

Experimental and theoretical studies of atomically thin quasi two-dimensional materials (typically related to some parent van der Waals layered crystals) and their nanostructures have revealed that these systems can exhibit highly unusual behaviors. In this talk, we discuss some theoretical studies of the electronic, transport and optical properties of such systems. We present results on graphene and graphene nanostructures as well as other quasi-2D systems such as monolayer and few-layer transition metal dichalcogenides (e.g., MoS$_{\mathrm{2}}$, MoSe$_{\mathrm{2}}$, WS$_{\mathrm{2}}$, and WSe$_{\mathrm{2}})$ and metal monochalcogenides (such as GaSe and FeSe). Owing to their reduced dimensionality, these systems present opportunities for unusual manifestation of concepts and phenomena that may not be so prominent or have not been seen in bulk materials. Symmetry and many-body interaction effects often play a critical role in shaping qualitatively and quantitatively their properties. Several quantum phenomena are discussed, including novel and dominant exciton effects, tunable magnetism, electron supercollimation by disorder, unusual plasmon behaviors, and possible enhanced superconductivity in some of these systems. We investigate their physical origins and compare theoretical predictions with experimental data.

*This work was supported by DOE under Contract No. DE-AC02-05CH11231 and by NSF under Grant No. DMR10-1006184. I would like to acknowledge collaborations with members of the Louie group and the experimental groups of Crommie, Heinz, Wang, and Zhang.

–

Authors

  • Steven G. Louie

    • University of California at Berkeley, Lawrence Berkeley National Lab
    • University of California - Berkeley and Lawrence Berkeley National Lab
    • Department of Physics, University of California at Berkeley; Materials Sciences Divisions, Lawrence Berkeley National Laboratory
    • Univ of California - Berkeley and Lawrence Berkeley National Lab
    • Department of Physics, UC Berkeley and Lawrence Berkeley National Lab
    • University of California, Berkeley and Lawrence Berkeley National Laboratory
    • University of California at Berkeley and Lawrence Berkeley National Laboratory
    • UC Berkeley and Lawrence Berkeley National Lab
    • University of California at Berkeley and Lawrence Berkeley National Lab
    • Physics Department, UC Berkeley and Lawrence Berkeley National Lab
    • Department of Physics, University of California, Berkeley, and Materials Science Division, Lawrence Berkeley National Lab, Berkeley, CA 94720, USA
    • UC Berkeley physics/ LBNL MSD