Aspects of quantum transport in DNA origami nanostructures and in topological Kondo insulator SmB6

Thesis

For the past seventy years, condensed matter physics has produced ever smaller and more energy efficient information processing devices based on quantum transport processes. In order to continue this trend into the future and also to develop platforms for the emerging industry of quantum computing it is necessary to explore new methods. This thesis details two studies performed with the aim of deepening our understanding of the quantum transport in meso- and nanoscale systems such that they might be used in future information processing.

In the first section, I discuss the fabrication, measurement and characterisation of nanogap devices and single molecule electronics. These devices are of strong interest for the role they could play in energy efficient classical computing and as novel qubit platforms. By exploiting DNA origami techniques developed by collaborators, devices can be fabricated with significantly higher yields than current methodologies. The major result of this is the fabrication of high yield nanogaps and a possible Copper porphyrin molecular device. This moves us significantly closer to achieving the deterministic fabrication of devices with multiple functional molecular components.

In the second section, I present a theoretical study of the surface states of SmB₆, a topological insulator. These materials are of strong interest in spintronics due to their spin polarised surface states. I demonstrate DFT studies that accurately reproduce some of the important experimentally observed features, providing insight into the role of interactions in the material.

Authors: Steggles, M

• DOI: 10.5287/ora-xvkqdxkbx
• Type of award: DPhil
• Level of award: Doctoral
• Awarding institution: University of Oxford
• Language: English