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Ising quantum Hall ferromagnet in magnetically doped quantum wells
J Jaroszyński1, T Andrearczyk, G Karczewski
1Institute of Physics, Polish Academy of Sciences, aleja Lotników 32/46, 02-668 Warszawa, Poland. jaroszy@magnet.fsu.edu
Physical Review Letters
|December 18, 2002
Summary
We observed an Ising quantum Hall ferromagnet in a (Cd,Mn)Te heterostructure with a high Curie temperature (T(C)) of 2 K. This ferromagnet is destroyed by domain excitations near its critical temperature.
Area of Science:
- Condensed matter physics
- Quantum Hall effect
- Spintronics
Background:
- The Ising quantum Hall ferromagnet is a novel quantum state observed in specific semiconductor heterostructures.
- Understanding its properties is crucial for advancing quantum computing and spintronic devices.
Purpose of the Study:
- To report the observation and characterization of an Ising quantum Hall ferromagnet.
- To investigate the factors influencing its Curie temperature and critical behavior.
Main Methods:
- Fabrication of a modulation-doped (Cd,Mn)Te heterostructure.
- Magnetoresistance measurements across a wide range of temperatures, magnetic fields, and tilt angles.
- Analysis incorporating Coulomb interactions and s-d coupling to Mn spin fluctuations.
Main Results:
- Observation of an Ising quantum Hall ferromagnet with a Curie temperature (T(C)) as high as 2 K.
- Field-induced Landau level crossing due to giant spin-splitting.
- Critical behavior of resistance spikes near T(C) indicating destruction by domain excitations.
Conclusions:
- The (Cd,Mn)Te heterostructure hosts a robust Ising quantum Hall ferromagnet.
- Domain excitations are identified as the mechanism destroying the ferromagnetism at the critical temperature.