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Giant planar Hall effect in epitaxial (Ga,Mn)as devices
H X Tang1, R K Kawakami, D D Awschalom
1Condensed Matter Physics 114-36, California Institute of Technology, Pasadena, California 91125, USA.
Physical Review Letters
|April 12, 2003
Summary
Researchers observed giant planar Hall effect in (Ga,Mn)As microdevices, enabling highly sensitive magnetic property measurements. This effect is significantly larger than in traditional metallic ferromagnets.
Area of Science:
- Condensed matter physics
- Materials science
- Spintronics
Background:
- The planar Hall effect (PHE) is a magnetoresistance phenomenon observed in ferromagnetic materials.
- Previous studies in metallic ferromagnets reported PHE values significantly smaller than those observed in semiconductor-based systems.
- Epitaxial (Ga,Mn)As is a promising material for spintronic applications due to its tunable magnetic properties.
Purpose of the Study:
- To investigate the Hall resistance behavior in microdevices patterned from epitaxial (Ga,Mn)As.
- To characterize the giant planar Hall effect in (Ga,Mn)As and compare it with metallic ferromagnets.
- To utilize the observed effect for sensitive measurements of magnetic anisotropy in (Ga,Mn)As.
Main Methods:
- Fabrication of microdevices from epitaxial (Ga,Mn)As layers.
- Application of swept, in-plane magnetic fields.
- Measurement of Hall resistance as a function of magnetic field angle.
Main Results:
- Observation of large Hall resistance jumps in (Ga,Mn)As microdevices.
- Quantification of a giant planar Hall effect, four orders of magnitude greater than in metallic ferromagnets.
- Deduction of magnetic anisotropy fields from the angle-dependent measurements.
Conclusions:
- Epitaxial (Ga,Mn)As exhibits an exceptionally large planar Hall effect.
- This giant PHE enables highly sensitive characterization of magnetic anisotropy.
- The findings provide valuable insights for the development of novel spintronic devices.