Jaroszyński J, Andrearczyk T, Karczewski G, Wróbel J, Wojtowicz T, Papis E, Kamińska E, Piotrowska A, Popović Dragana, Dietl T
Institute of Physics, Polish Academy of Sciences, aleja Lotników 32/46, 02-668 Warszawa, Poland.
Phys Rev Lett. 2002 Dec 23;89(26):266802. doi: 10.1103/PhysRevLett.89.266802. Epub 2002 Dec 10.
We report on the observation of the Ising quantum Hall ferromagnet with Curie temperature T(C) 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-->T(C) corroborates theoretical suggestions that the ferromagnet is destroyed by domain excitations.
我们报道了在调制掺杂的（Cd，Mn）Te异质结构中观察到居里温度T（C）高达2K的伊辛量子霍尔铁磁体。在该系统中，由于巨大的自旋分裂效应，发生了朗道能级的场致交叉。考虑到库仑电子-电子相互作用和与Mn自旋涨落的s-d耦合，讨论了在很宽的温度、磁场、倾斜角和电子密度范围内收集的磁阻数据。在T→T（C）时电阻“尖峰”的临界行为证实了铁磁体被畴激发破坏的理论推测。
