Related Experiment Video
Updated: Jun 21, 2026
15:58
Measurement of Coherence Decay in GaMnAs Using Femtosecond Four-wave Mixing
Published on: December 3, 2013
Intrinsic coupling between current and domain wall motion in (Ga,Mn)As.
Kjetil Magne Dørheim Hals1, Anh Kiet Nguyen, Arne Brataas
1Department of Physics, Norwegian University of Science and Technology, NO-7491, Trondheim, Norway.
Physical Review Letters
|August 8, 2009
Summary
We investigated domain wall motion and induced currents in (Ga,Mn)As. Spin-orbit interaction significantly influences damping and spin-transfer torque, enabling experimental detection of domain wall motion via voltage.
Area of Science:
- Condensed matter physics
- Spintronics
- Materials science
Background:
- Domain wall motion is crucial for spintronic devices.
- Understanding current-induced domain wall dynamics is key for device applications.
- The role of spin-orbit interaction in (Ga,Mn)As requires further investigation.
Purpose of the Study:
- To analyze current-induced domain wall motion and its reciprocal effect in (Ga,Mn)As.
- To express Onsager coefficients using scattering matrices.
- To elucidate the dominant factors governing Gilbert damping and spin-transfer torque.
Main Methods:
- Theoretical analysis using scattering matrices.
- Numerical calculations of Onsager coefficients.
- Investigation of spin-orbit interaction effects.
Main Results:
- Onsager coefficients are determined by scattering matrices.
- Effective Gilbert damping (alphaw) and spin-transfer torque (betaw) in (Ga,Mn)As are dominated by spin-orbit interaction and domain wall scattering.
- Calculated alphaw ≈ 0.01 and betaw ≈ 1 for dirty (Ga,Mn)As.
Conclusions:
- Spin-orbit interaction plays a critical role in domain wall dynamics in (Ga,Mn)As.
- The large betaw parameter facilitates experimental observation of domain wall motion via induced currents or voltages.
- This study provides insights into the fundamental physics of domain wall motion for potential spintronic applications.
Related Concept Videos
01:23Magnetic Field due to Moving Charges
A stationary charge creates and interacts with the electric field, while a moving charge creates a magnetic field.
Consider a point charge moving with a constant velocity. Like the electric field, the magnetic field at any point is directly proportional to the magnitude of the charge and inversely proportional to the square of the distance between the source point and the field point. However, unlike the electric field, the magnetic field is always perpendicular to the plane containing the line...
Consider a point charge moving with a constant velocity. Like the electric field, the magnetic field at any point is directly proportional to the magnitude of the charge and inversely proportional to the square of the distance between the source point and the field point. However, unlike the electric field, the magnetic field is always perpendicular to the plane containing the line...
01:13Magnetic Force Between Two Parallel Currents
Two long, straight, and parallel current-carrying conductors exert a force of equal magnitude on one another. The direction of the force depends on the current direction in the conductors.
The force exerted by the magnetic field due to the first conductor over a finite length of the second conductor is given as the product of the current in the second conductor and the vector product of the length vector along the current element and the field due to the first conductor. According to the...
The force exerted by the magnetic field due to the first conductor over a finite length of the second conductor is given as the product of the current in the second conductor and the vector product of the length vector along the current element and the field due to the first conductor. According to the...
01:27Magnetic Field Due To A Thin Straight Wire
Consider an infinitely long straight wire carrying a current I. The magnetic field at point P at a distance a from the origin can be calculated using the Biot-Savart law.
01:16Magnetic Field Of A Current Loop
Consider a circular loop with a radius a, that carries a current I. The magnetic field due to the current at an arbitrary point P along the axis of the loop can be calculated using the Biot-Savart law.
01:11P-N junction
A p-n junction is formed when p-type and n-type semiconductor materials are joined together. At the interface of the p-n junction, holes from the p-side and electrons from the n-side begin to diffuse into the opposite sides due to the concentration gradient. This diffusion of carriers leads to a region around the junction where there are no free charge carriers, known as the depletion region. The charge density within the depletion region for the n-side and p-side can be described by the...
01:22Magnetic Force On Current-Carrying Wires: Example
In a magnetic field, moving charges encounter a force. If a wire contains these moving charges, i.e., if the wire is carrying a current, then a force acts on the wire as well. Consider a pair of flexible leads holding a wire that is 40 cm long and 10 g in weight in a horizontal position. The wire is placed in a constant magnetic field of 0.40 T, as shown in Figure 1(a). Determine the magnitude and direction of the current flowing in the wire needed to remove the tension in the supporting leads.