Engineering interaction effects in low-dimensional semiconductor nanostructures

A comprehensive understanding of the transport phenomena in low-dimensional electron systems is incomplete without considering the role of electron-electron interactions. Many of the currently studied quantum-transport effects, such as, for example, the 0.7-anomaly, Wigner crystallization, Coulomb drag and fractional quantisation, are largely dominated by electron-electron interactions. Thus, to reveal the role of interactions in such low-dimensional systems, novel schemes must be introduced to enhance many-body effects which can then be measured. One of the methods to enhance the interaction effects is to fabricate suspended nanostructures exploiting high mobility two-dimensional electron gas. In such systems, the electron-electron interactions get enhanced due to both partial confinement of electric field within a thin membrane having a high dielectric constant and modification of the phonon spectrum. In this research project, the PhD student will develop understanding of the field, and spend considerable time in the cleanroom fabricating nanoscale devices for detailed quantum transport measurement. They will have access to various training programmes directly related to their PhD project such as courses on programming languages, workshop on low-noise electrical measurements and data analysis as well opportunities for networking with industries. The student will be training on using ultra-low temperature dilution refrigerator with high magnetic field for performing transport measurement on the fabricated nanoscale devices. They will perform transport in strongly interacting suspended and non-suspended, coupled quantum point contacts and quantum wires to investigate new fundamental quantum physics such as the non-magnetic fractional states, spin and charge phases including quantum phase transition.

The current research project is in line with the EPSRC thematic areas such as physical and engineering sciences and quantum technologies.