Related Experiment Video
Updated: Nov 11, 2025
11:41
Magnetic Tweezers for the Measurement of Twist and Torque
Published on: May 19, 2014
23.5K
Large amplitude spin-Hall oscillations due to field-like torque
R Arun1, R Gopal2, V K Chandrasekar2
1Department of Nonlinear Dynamics, School of Physics, Bharathidasan University, Tiruchirapalli-620024, India.
Summary
Large amplitude spin-Hall oscillations were observed in ferromagnetic layers without external fields. Researchers tuned oscillation frequencies from 2 GHz to 80 GHz using current and field-like torque, enhancing both frequency and Q-factor.
Area of Science:
- Spintronics
- Condensed Matter Physics
Background:
- Spin-Hall effect is crucial for spintronic devices.
- Controlling spin dynamics without external fields is a key challenge.
Purpose of the Study:
- To investigate large amplitude spin-Hall oscillations in a specific ferromagnetic material.
- To explore the role of field-like torque in generating these oscillations.
- To analyze the tunability of oscillation frequency and Q-factor.
Main Methods:
- Analytical study of spin dynamics.
- Numerical simulations (implied by frequency tuning).
Main Results:
- Identified large amplitude spin-Hall oscillations without polarizers or external fields.
- Confirmed the possibility of oscillations driven by field-like torque.
- Achieved frequency tuning from approximately 2 GHz to 80 GHz via current.
- Observed enhancement of oscillation frequency and Q-factor through current and field-like torque.
Conclusions:
- Field-like torque can induce significant spin-Hall oscillations.
- Current and field-like torque offer effective control over oscillation frequency and quality factor.
- This work paves the way for novel spintronic devices.
Related Concept Videos
01:13Torque On A Current Loop In A Magnetic Field
5.2K
The most common application of magnetic force on current-carrying wires is in electric motors. These consist of loops of wire, which are placed between the magnets with a magnetic field. When current flows through the loops, the magnetic field applies torque, which causes the shaft to rotate, thus converting electrical energy to mechanical energy.
Consider a rectangular current-carrying loop containing N turns of wire, placed in a uniform magnetic field. The net force on a current-carrying loop...
Consider a rectangular current-carrying loop containing N turns of wire, placed in a uniform magnetic field. The net force on a current-carrying loop...
5.2K
01:08Spin–Spin Coupling Constant: Overview
1.2K
In bromoethane, the three methyl protons are coupled to the two methylene protons that are three bonds away. In accordance with the n+1 rule, the signal from the methyl protons is split into three peaks with 1:2:1 relative intensities. The methylene protons appear as a quartet, with the relative intensities of 1:3:3:1.
Qualitatively, any spin plus-half nucleus polarizes the spins of its electrons to the minus-half state. Consequently, the paired electron in the hydrogen–carbon bond must...
Qualitatively, any spin plus-half nucleus polarizes the spins of its electrons to the minus-half state. Consequently, the paired electron in the hydrogen–carbon bond must...
1.2K
01:09Torsional Pendulum
6.5K
A torsional pendulum involves the oscillation of a rigid body in which the restoring force is provided by the torsion in the string from which the rigid body is suspended. Ideally, the string should be massless; practically, its mass is much smaller than the rigid body's mass and is neglected.
As long as the rigid body's angular displacement is small, its oscillation can be modeled as a linear angular oscillation. The amplitude of the oscillation is an angle. The role of mass is played...
As long as the rigid body's angular displacement is small, its oscillation can be modeled as a linear angular oscillation. The amplitude of the oscillation is an angle. The role of mass is played...
6.5K
01:23Atomic Nuclei: Nuclear Relaxation Processes
891
In the absence of an external magnetic field, nuclear spin states are degenerate and randomly oriented. When a magnetic field is applied, the spins begin to precess and orient themselves along (lower energy) or against (higher energy) the direction of the field. At equilibrium, a slight excess population of spins exists in the lower energy state. Because the direction of the magnetic field is fixed as the z-axis, the precessing magnetic moments are randomly oriented around the z-axis.
891
01:15Torque Free Motion
637
The torque-free motion refers to the movement of a rigid body in space when no external torques are acting upon it. This type of motion can be observed in environments where there are no external forces or frictions, like in outer space. For example, a rotation of Mars in space is a torque-free motion. Mars is an axisymmetric object, meaning it has an axis of symmetry along which it rotates, designated as the z-axis. The rotating frame of reference is defined such that the center of mass of...
637
01:03Atomic Nuclei: Nuclear Spin State Overview
1.5K
NMR-active nuclei have energy levels called 'spin states' that are associated with the orientations of their nuclear magnetic moments. In the absence of a magnetic field, the nuclear magnetic moments are randomly oriented, and the spin states are degenerate. When an external magnetic field is applied, the spin states have only 2 + 1 orientations available to them. A proton with = ½ has two available orientations. Similarly, for a quadrupolar nucleus with a nuclear spin value of one, the...
1.5K