Effects of electron-hole interactions in single-particle excitations within the <i>GW</i> approach

ORAL

Abstract

There are a number of schemes in the literature to do “self-consistent” GW calculations at different levels going beyond the G0W0 approximation. For single-particle excitations (e.g., the quasiparticle bandgap in semiconductors), a straightforward self-consistent update of both the single-particle Green’s function G and the screened Coulomb interaction W generally gives less satisfactory results than those from the G0W0 approach as compared to experiment, which is due to an under-screening introduced and accumulated in the treatment of dielectric screening at the random phase approximation (RPA) level, where electron-hole interactions are neglected. In this work, we investigate the importance of electron-hole interactions in modifying W and hence the GW self-energy, as well as in reshaping single-particle excitations at the GW level. We present our theoretical formalism, along with first-principles results for several conventional semiconductors.

*This work was supported by the Theory of Materials Program and the C2SEPEM at LBNL funded by the U.S. DOE under Contract No. DE-AC02-05CH11231, and by the National Science Foundation. Computational resources have been provided by NERSC and XSEDE.

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Presenters

  • Meng Wu

    • University of California, Berkeley
    • Lawrence Berkeley National Laboratory and University of California at Berkeley
    • Department of Physics, University of California at Berkeley and Lawrence Berkeley National Laboratory

Authors

  • Meng Wu

    • University of California, Berkeley
    • Lawrence Berkeley National Laboratory and University of California at Berkeley
    • Department of Physics, University of California at Berkeley and Lawrence Berkeley National Laboratory

  • Zhenglu Li

    • Department of Physics, University of California, Berkeley, Berkeley, California 94720, USA and Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, C
    • Lawrence Berkeley National Laboratory and University of California at Berkeley
    • Department of Physics, University of California at Berkeley and Lawrence Berkeley National Laboratory

  • Steven Louie

    • University of California at Berkeley, and Lawrence Berkeley National Laboratory
    • Department of Physics, University of California, Berkeley, Berkeley, California 94720, USA and Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, C
    • University of California, Berkeley
    • Department of Physics, University of California, Berkeley
    • Lawrence Berkeley National Laboratory and University of California at Berkeley
    • Department of Physics, University of California at Berkeley and Lawrence Berkeley National Laboratory
    • Department of Physics, UC Berkeley
    • Physics, Unviersyt of Calfornia, Berkeley
    • Physics, University of California, Berkeley
    • Physics, University of California, Berkeley and Lawrence Berkeley National Lab