We report on the observation of the Ising quantum Hall ferromagnet with Curie temperature TC as high as 2 K in a modulation-doped (Cd,Mn)Te heterostructure. In this system field-induced crossing of Landau levels occurs due to the giant spin-splitting effect. Magnetoresistance data, collected over a wide range of temperatures, magnetic fields, tilt angles, and electron densities, are discussed taking into account both Coulomb electron-electron interactions and s−d coupling to Mn spin fluctuations. The critical behavior of the resistance ``spikes'' at T→TC corroborates theoretical suggestions that the ferromagnet is destroyed by domain excitations.
@article{arxiv.cond-mat/0205296,
title = {Ising Quantum Hall Ferromagnet in Magnetically Doped Quantum Wells},
author = {J. Jaroszynski and T. Andrearczyk and G. Karczewski and J. Wrobel and T. Wojtowicz and E. Papis and E. Kaminska and A. Piotrowska and Dragana Popovic and T. Dietl},
journal= {arXiv preprint arXiv:cond-mat/0205296},
year = {2009}
}