Quantum Hall Ferromagnetism In InSb Heterostructures

Abstract

We report on the observation of quantum Hall ferromagnetism in two-dimensional electronic systems (2DES) based in single InSb/InAlSb quantum wells. Magnetoresistance measurements revealed well resolved quantum Hall ferromagnetic states in high density InSb samples at filling factors ν = 2 and ν = 3. These states are identified by persistent quantum Hall (QH) minima under tilted magnetic fields, accompanied by broad resistance peaks attributed to dissipative transport along domain wall boundaries between different pseudospin polarized states. The InSb system can be tuned from the regime where many-body effects are dominant to the single particle regime by reducing the carrier concentration. Particular to InSb, activation energy data suggest that transport within quantum Hall ferromagnets is related to variable range hopping with characteristic temperature of the order of 9 K.