Application Description
The Hall effect appears as the potential difference induced perpendicularly to the moving charge carriers and an external magnetic field. The effect is widely used for the characterization of materials and magnetic-field sensing.
Material characterization
When a material is characterized, it is exposed to a known magnetic field B. At the same time, the Hall voltage VXY (see figure), the voltage across the sample VXX, and the current IR through the material are measured. From these measurements, it is possible to infer material properties such as the charge carrier density, the charge carrier polarity, the charge carrier mobility, and the material's conductivity.
This technique is also used to measure novel physical properties of two-dimensional electron gas (2DEG) materials by measuring the quantum Hall effect and its many derivatives: integer, fractional, spin, inverse spin, and more.
Magnetic-field sensing
When the material properties are well-known, the Hall effect can be used to infer the external magnetic field over many orders of magnitude. The measurements can be carried out with DC voltages applied to the sample, however, AC measurements usually lead to faster and more accurate results. Further benefits of AC measurements include higher precision and sensitivity generally leading to a larger signal-to-noise ratio (SNR) over a wider measurement range.