Sample interview questions: Can you explain the concept of magnetoresistance and its applications in solid-state physics?
Sample answer:
Concept of Magnetoresistance
Magnetoresistance (MR) is the change in electrical resistance of a material under the influence of an applied magnetic field. When a magnetic field is applied perpendicular to the direction of current flow, the resistance can increase (positive MR) or decrease (negative MR).
Origin of Magnetoresistance
The origin of MR can be attributed to either:
- Lorentz Force: In metals, the magnetic field exerts a Lorentz force on the charge carriers (electrons), deflecting their trajectories and increasing resistivity.
- Spin-Orbit Interaction: In some materials, the magnetic field interacts with the spin of the charge carriers, altering their energy levels and scattering rates, leading to MR.
Applications of Magnetoresistance in Solid-State Physics
- Magnetic Sensors: MR-based devices, such as giant magnetoresistance (GMR) and tunneling magnetoresistance (TMR) sensors, detect and measure magnetic fields with high sensitivity and are used in applications like magnetic read heads in hard-disk drives.
- Spintronics: MR is crucial in the study of spintronics, where the spin degrees of freedom of charge carriers are manipulated for novel electronic devices with enhanced performance and energy efficiency.
Source: https://hireabo.com/job/5_0_12/Solid-State%20Physicist