Low temperature spintronics : probing charge and spin states with two-dimensional electron gas

This thesis is based on two low temperature experiments in spintronics - physics and engineering of electronic spins. The measurements were performed on a GaAs/AlGaAs two-dimensional electron gas with geometries defined by tunable surface gates. The first experiment is about detection of electrons i...

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Main Author: Yu, Wing Wa
Format: Others
Language:English
Published: University of British Columbia 2009
Online Access:http://hdl.handle.net/2429/12580
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spelling ndltd-LACETR-oai-collectionscanada.gc.ca-BVAU.-125802013-06-05T04:17:45ZLow temperature spintronics : probing charge and spin states with two-dimensional electron gasYu, Wing WaThis thesis is based on two low temperature experiments in spintronics - physics and engineering of electronic spins. The measurements were performed on a GaAs/AlGaAs two-dimensional electron gas with geometries defined by tunable surface gates. The first experiment is about detection of electrons in a quantum dot. A quantum point contact (QPC) and a quantum wire (QW) is coupled to a single-lead few-electron quantum dot. By measuring the conductance of the QPC and the QW, one can gain information on the average number of electrons in the dot as well as energy-level structure of the dot. The second experiment investigates anisotropy of spin-orbit interaction in GaAs/AlGaAs heterostructure by measuring spin polarization in a narrow channel. Polarized electrons are injected into the channel through a spin-selective injector QPC and diffuse towards the end of the channel. This diffusion generates a pure spin current and the spin polarization 25 microns away is measured by a detector QPC. A periodic spin-orbit field induced by motion of the electrons in the channel causes the spins to resonate with external magnetic field. Spin-orbit anisotropy is demonstrated by the different resonance strength observed in channels aligned along two different crystal axes.University of British Columbia2009-08-27T13:36:05Z2009-08-27T13:36:05Z20092009-08-27T13:36:05Z2009-11Electronic Thesis or Dissertation1297593 bytesapplication/pdfhttp://hdl.handle.net/2429/12580eng
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language English
format Others
sources NDLTD
description This thesis is based on two low temperature experiments in spintronics - physics and engineering of electronic spins. The measurements were performed on a GaAs/AlGaAs two-dimensional electron gas with geometries defined by tunable surface gates. The first experiment is about detection of electrons in a quantum dot. A quantum point contact (QPC) and a quantum wire (QW) is coupled to a single-lead few-electron quantum dot. By measuring the conductance of the QPC and the QW, one can gain information on the average number of electrons in the dot as well as energy-level structure of the dot. The second experiment investigates anisotropy of spin-orbit interaction in GaAs/AlGaAs heterostructure by measuring spin polarization in a narrow channel. Polarized electrons are injected into the channel through a spin-selective injector QPC and diffuse towards the end of the channel. This diffusion generates a pure spin current and the spin polarization 25 microns away is measured by a detector QPC. A periodic spin-orbit field induced by motion of the electrons in the channel causes the spins to resonate with external magnetic field. Spin-orbit anisotropy is demonstrated by the different resonance strength observed in channels aligned along two different crystal axes.
author Yu, Wing Wa
spellingShingle Yu, Wing Wa
Low temperature spintronics : probing charge and spin states with two-dimensional electron gas
author_facet Yu, Wing Wa
author_sort Yu, Wing Wa
title Low temperature spintronics : probing charge and spin states with two-dimensional electron gas
title_short Low temperature spintronics : probing charge and spin states with two-dimensional electron gas
title_full Low temperature spintronics : probing charge and spin states with two-dimensional electron gas
title_fullStr Low temperature spintronics : probing charge and spin states with two-dimensional electron gas
title_full_unstemmed Low temperature spintronics : probing charge and spin states with two-dimensional electron gas
title_sort low temperature spintronics : probing charge and spin states with two-dimensional electron gas
publisher University of British Columbia
publishDate 2009
url http://hdl.handle.net/2429/12580
work_keys_str_mv AT yuwingwa lowtemperaturespintronicsprobingchargeandspinstateswithtwodimensionalelectrongas
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