Project Info

Designing and constructing a probe for low temperature electrical transport measurements

Bo Wu | bwu@mines.edu

The response of materials to changes in temperature (T) and magnetic field (H) can provide insight into the physical origins of scientifically interesting properties or identify technologically useful phases. In addition to inducing thermal phase transitions, low temperatures are often required to reveal quantum mechanical properties or other effects obfuscated by high thermal energy at room temperature. Magnetic fields interact with conduction electrons and magnetic moments, can align domains or spins, and can induce quantum phase transitions. For example, magnetotransport measurements can be used to study the electronic structure on a quantum level, magnetic frustration, and the classical and quantum Hall effects (quantization of conductance in low temperatures and high fields). Magnetic fields are required in different quantum bit schemes (e.g., silicon-based, nitrogen vacancy centers) to lift spin degeneracy via the Zeeman effect, allowing initialization and readout of single electron spins. Furthermore, in the H-T phase diagram of many classes of materials, fundamentally fascinating regions exist in which quasiparticles emerge that can be leveraged in device applications, such as skyrmions for next-generation spintronic devices.

In this project, the student will design and construct a measurement probe to be used in our magnetometer to collect electrical transport measurements in variable temperatures (1.8-300K) and magnetic fields (0-7T). The student will also set up an equipment rack to source and measure currents and voltages as well as write computer programs to collect measurements on a variety of superconducting and magnetic samples. (For example, the student would be asked to write a program to collect resistance versus temperature curves for a superconductor and Hall effect measurements on magnetic samples known to host skyrmions).

More Information

1. Magnetometer: https://www.qdusa.com/products/mpms3.html
2. Student will build a probe similar to this one: https://www.qdusa.com/sitedocs/productBrochures/1505-604.pdf

Grand Engineering Challenge: Engineer the tools of scientific discovery