Physical mechanisms for interface-mediated intervalley coupling in Si

ORAL

Abstract

The conduction band degeneracy in Si is detrimental to quantum computing based on spin qubits, for which a nondegenerate ground orbital state is desirable. This degeneracy is lifted at an interface with an insulator as the spatially abrupt change in the conduction band minimum leads to intervalley scattering. We present a theoretical study of the interface-induced valley splitting in Si that provides simple criteria for optimal fabrication parameters to maximize this splitting. Our work emphasizes the relevance of different interface-related properties to the valley splitting.

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Authors

  • Andre Saraiva

    UFRJ / Univ. of Wisconsin

  • Maria Calderon

    Instituto de Ciencia de Materiales de Madrid (ICMM-CSIC), Instituto de Ciencia de Materiales de Madrid (CSIC)

  • Xuedong Hu

    University at Buffalo, Department of Physics, University of Buffalo, SUNY, Department of Physics, University at Buffalo, The State University of New York, Department of Physics, University at Buffalo, SUNY, Buffalo, NY 14260-1500, University at Buffalo, SUNY, SUNY at Buffalo, Department of Physics, University at Buffalo, the State University of New York

  • S. Das Sarma

    University of Maryland, Condensed Matter Theory Center and Center for Nanophysics and Advanced Materials, Department of Physics, University of Maryland, College Park, Condensed Matter Theory Center and Joint Quantum Institute, Department of Physics, University of Maryland, College Park, MD 20742, Condensed Matter Theory Center and Joint Quantum Institute, Department of Physics, University of Maryland, College Park, Maryland, USA, University of Maryland, College Park, University of Maryland-College Park, Condensed Matter Theory Center, Department of Physics, University of Maryland, College Park MD 20742-4111, Univ. of Maryland, University of Maryland, College Park, Maryland, USA, Condensed Matter Theory Center, Department of Physics, University of Maryland, College Park, Maryland 20742-4111

  • Belita Koiller

    Univ. Federal do Rio de Janeiro, Instituto de Fisica, UFRJ