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Resistance spikes at transitions between quantum hall ferromagnets
E P De Poortere1, E Tutuc, S J Papadakis
1Department of Electrical Engineering, Princeton University, Princeton, NJ 08544, USA. poortere@ee.princeton.edu
Science (New York, N.Y.)
|November 25, 2000
Summary
First-order magnetic transitions were observed in two-dimensional electron systems within aluminum arsenide quantum wells. These transitions, marked by resistance spikes, reveal insights into magnetic domain dissipation and metallic ferromagnetism.
Area of Science:
- Condensed matter physics
- Quantum materials science
Background:
- Two-dimensional electron systems (2DES) exhibit complex magnetic behaviors.
- Understanding magnetic transitions is crucial for developing novel electronic devices.
Purpose of the Study:
- To investigate first-order magnetic transitions in 2DES.
- To analyze the role of magnetic domains in energy dissipation.
- To determine changes in exchange-correlation energy during magnetic transitions.
Main Methods:
- Fabrication of aluminum arsenide (AlAs) quantum wells.
- Experimental measurements of sample resistance in combined parallel and perpendicular magnetic fields.
- Analysis of hysteretic resistance spikes.
Main Results:
- Observed first-order magnetic transitions in AlAs 2DES at low carrier densities.
- Identified hysteretic resistance spikes corresponding to transitions between different partial magnetization states.
- Demonstrated that magnetic domains significantly increase energy dissipation during transitions.
- Quantified the change in exchange-correlation energy across the magnetic transition.
Conclusions:
- The study confirms first-order magnetic transitions in 2DES.
- Findings highlight the impact of magnetic domains on dissipation in ferromagnetic materials.
- The results provide a method to probe exchange-correlation energy, advancing the understanding of metallic ferromagnetism.
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