| Experiment Guide |
| 1. Pre-Lab |
| 2. Part 1 |
| 3. Part 2 |
| Related Material |
|
1. Melissinos (2003) 63 - 71 |
| 2. HP 3478A Multimeter Manual |
| Useful Links |
| 1. Wikipedia Article |
| 2. Quantum Hall Effect |
| 3. Spin Hall Effect |
| 4. Fractional Quantum Hall Effect |
| 5. Nobel Prize I |
| 6. Nobel Prize II |
Overview
Electrical resistivity is a basic measure of how well a material conducts electrical current. When a magnetic field is applied non-collinearly to the current direction, the Lorentz force bends the trajectory of charge carriers and leads to a potential difference. This is known as the Hall effect, named after Edwin Hall who discovered it in 1879. A figure of merit is the Hall coefficient, which is characteristic of charge carriers present in the material. There are a few variations of this effect (Nobel Prizes in 1985, 1998), see discussions at the Useful Links. Additionally, when certain magnetic heterostructures are placed inside a magnetic field, the spin-dependent scattering process can lead to a large change in their electrical resistance, or a giant magnetoresistance effect (GMR, Nobel Prize in 2007). In this experiment you will first explore electrical resistivity and the GMR effect in a metallic Co/Cu multilayer thin film; you will then measure the temperature dependent resistivity and Hall coefficient of a semiconductor germanium crystal.
