Nanoscale quantum transport for quantum information processing
| dc.comment.hidden | My thesis contains three of my published works. Two of them in APS journals and one in Scientific Reports. For reproducing material in my thesis (as author) I do not need permission as you can see below. As the author of an APS-published article, may I include my article or a portion of my article in my thesis or dissertation? Yes, the author has the right to use the article or a portion of the article in a thesis or dissertation without requesting permission from APS, provided the bibliographic citation and the APS copyright credit line are given on the appropriate pages. Material in a contribution submitted to Scientific Reports may also have been published as part of a PhD or other academic thesis. | en |
| dc.contributor.author | Qassemi Maloomeh, Farzad | |
| dc.date.accessioned | 2013-04-25T19:21:53Z | |
| dc.date.available | 2013-04-25T19:21:53Z | |
| dc.date.issued | 2013-04-25T19:21:53Z | |
| dc.date.submitted | 2012 | |
| dc.description.abstract | In this thesis, I study quantum transport of electron (e.g., current and noise) in quantum dots exploring microscopic processes responsible for spin-relaxation in double quantum dots in Pauli spin blockade regime. This is a regime where current is blocked due to the spin configuration of electrons in the dot. The Pauli spin blockade provides a means for preparation, manipulation and readout in spin qubits. Hence, understanding the underlying mechanism which lifts this blockade is extremely important. First, I have developed a theory of spin-flip cotunneling (higher order tunneling) processes in double quantum dots in the Pauli spin blockade regime. Utilizing this theory, I have calculated the full analytical dependence of the stationary current on applied magnetic fields, gate voltages, and an inter-dot tunnel coupling in Pauli spin blockade. This work is important for understanding the nature of leakage, especially in systems where other spin-flip mechanisms (due, e.g., hyperfine coupling to nuclear spins or spin-orbit coupling) are weak, including silicon and carbon nanotube or graphene quantum dots. This theory explains recent experiments on carbon nanotubes and silicon double quantum dot. In addition, I propose a new scheme based on the current noise to probe spin relaxation mechanisms in double quantum dot in the Pauli spin blockade regime, where spin-selection rule applies. As a result, I provide a simple closed-form expression which can be used to fit experimental data to extract multiple spin-relaxation rates, even at very low energy splitting. This method allows for the characterization of different aspects of decay process in these systems. | en |
| dc.identifier.uri | http://hdl.handle.net/10012/7451 | |
| dc.language.iso | en | en |
| dc.pending | false | en |
| dc.publisher | University of Waterloo | en |
| dc.subject | Quantum Information | en |
| dc.subject | Spintronics | en |
| dc.subject.program | Physics | en |
| dc.title | Nanoscale quantum transport for quantum information processing | en |
| dc.type | Doctoral Thesis | en |
| uws-etd.degree | Doctor of Philosophy | en |
| uws-etd.degree.department | Physics and Astronomy | en |
| uws.peerReviewStatus | Unreviewed | en |
| uws.scholarLevel | Graduate | en |
| uws.typeOfResource | Text | en |