Evidence of a Hybridization Gap in ``Semimetallic'' InAs/GaSb Systems

Abstract

InAs/GaSb composite quantum wells sandwiched by AlSb are studied by using capacitance-voltage, quantum Hall, and three-terminal transfer measurements. Our data reveal a positive energy gap resulting from the hybridization of in-plane dispersions of electrons in InAs and holes in GaSb for conventionally recognized ``semimetallic'' InAs/GaSb heterostructures.