Possible Jahn-Teller effect in Si inverse layers

Abstract

The Jahn-Teller effect in a bivalley Si͑100͒ heterostructure under conditions of the quantum Hall effect at integer filling factors ϭ1, 2, and 3 is studied. This system is described by an SU͑4͒ hidden symmetry. At ϭ2 static and dynamic lattice deformations give rise to an easy-plane anisotropy and an antiferromagnetic exchange, and lift the valley degeneracy. At ϭ1, and 3 Coulomb interaction is essential to produce a weak easy-plane anisotropy. At ϭ2 three phases, ferromagnetic, canted antiferromagnetic, and spin-singlet, have been found. The anisotropy energy of charged skyrmion excitation in every phase is calculated.

Chapter 3 Transport in a Two-Dimensional Disordered Electron Liquid with Isospin Degrees of Freedom

“…In order to describe 2D two-valley disordered electron system realized in Si(001)-MOSFET, it is convenient to write the electron annihilation operator with spin projection σ/2 on z axis as follows 117,118 :…”

Electronic properties in a two-dimensional disordered electron liquid: Spin-valley interplay

“…For the case of a Si͑001͒-MOSFET, which is of main interest for us, we write an electron annihilation operator with the help of oneelectron orbital functions as 22,23 …”

Spin-valley interplay in two-dimensional disordered electron liquid

“…The vector Q = (0, 0, Q) corresponds to the shortest distance between the valley minima in the reciprocal space: Q ∼ a −1 lat , with a lat being the lattice constant. 1,15 In the path-integral formulation 2D interacting electrons in the presence of the random potential V (r) are described by the following grand partition function…”