Ising quantum Hall ferromagnet in magnetically doped quantum wells.
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.
Jaroszyński
J
J
Institute of Physics, Polish Academy of Sciences, aleja Lotników 32/46, 02-668 Warszawa, Poland. jaroszy@magnet.fsu.edu
Andrearczyk
T
T
Karczewski
G
G
Wróbel
J
J
Wojtowicz
T
T
Papis
E
E
Kamińska
E
E
Piotrowska
A
A
Popović
Dragana
D
Dietl
T
T