Conductivity activation energy for bilayer hetero-structures at integer filling numbers

Falko, V.; Iordanski, S. V.; Kashuba, A.

Conductivity activation energy for bilayer hetero-structures at integer filling numbers

Authors

Falko, V.

Iordanski, S. V.

Kashuba, A.

Description

We report on study of low-energy excitations in a bilayer hetero-structure 2D electron gas. We split the bilayer Hamiltonian into SU(4)-symmetric part and the anisotropy part and treat the latter as a perturbation. We find that both Goldstone and the charged excitations - skyrmions - are goverened by the non-linear Sigma Model. We calculate the anisotropic energy gap of the skyrmion to have a prominent minimum in the canted antiferromagnetic phase of bilayer. We compare our findings with the results of recent experiments.
latex, 25 pages, 5 figures