Investigating many body effects in quantum structures

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The objective of this experimental Ph.D. project is to investigate many-body effects in low-dimensional semiconductor nanostructures using quantum transport at cryogenic temperatures. In recent years, a variety of new quantum effects have been proposed as well as discovered when a low-dimensional semiconductor nanostructure is electrostatically confined to create a one-dimensional (1D) quantum structure exhibiting unique characteristics previously unknown. One of the characteristics is the observation of fractional quantised conductance through a weakly confined quasi-1D quantum wire. The conductance through a 1D quantum wire is commonly represented by N(2e2/h), where N = 1,2,3 ... is the number of 1D energy subbands. When 1D electrons are subjected to strong Coulomb interactions, a line of 1D electrons rearranges itself into a zigzag which remarkably is found to exhibit fractional quantised conductance below 2e2/h. The many-body effects of these recently discovered phenomena will be comprehensively studied in new experimental devices which will produce better tuning of the confinement potential, as well as the ability to customise the separation between neighbouring electrons. A significant component of the project will be investigating the zigzag phase, which is expected to possess numerous quantum properties including electron pairings and entanglement. In addition to cleanroom training for fabricating quantum devices, the student will receive extensive training and supervision for performing low-noise quantum transport measurements at extremely low temperatures and high magnetic fields. Furthermore, additional training programmes would be available through UCL, as well as the opportunity to network with interdisciplinary research teams and industries. There will be many opportunities to present work at national and international conferences, and to build contacts with researchers and industry partners. The project will have broad implications for the next generation of quantum computing devices as well as new fundamental quantum foundations of condensed matter physics.The current research project falls into the EPSRC thematic areas such as physical and engineering sciences and quantum technologies.