title: Polarization-driven topological insulator transition in a GaN/InN/GaN quantum well.
abstract: Topological insulator (TI) states have been demonstrated in materials with a narrow gap and large spin-orbit interactions (SOI). Here we demonstrate that nanoscale engineering can also give rise to a TI state, even in conventional semiconductors with a sizable gap and small SOI. Based on advanced first-principles calculations combined with an effective low-energy k · p Hamiltonian, we show that the intrinsic polarization of materials can be utilized to simultaneously reduce the energy gap and enhance the SOI, driving the system to a TI state. The proposed system consists of ultrathin InN layers embedded into GaN, a layer structure that is experimentally achievable.
authors.affiliation: Materials Research Laboratory and Materials Department, University of California, Santa Barbara, California 93106-5050, USA. miaoms@engineering.ucsb.edu
authors.forename: M S
authors.initials: MS
authors.lastname: Miao
authors.forename: Q
authors.initials: Q
authors.lastname: Yan
authors.forename: C G
authors.initials: CG
authors.lastname: Van de Walle
authors.forename: W K
authors.initials: WK
authors.lastname: Lou
authors.forename: L L
authors.initials: LL
authors.lastname: Li
authors.forename: K
authors.initials: K
authors.lastname: Chang