Please use this identifier to cite or link to this item: http://scholarbank.nus.edu.sg/handle/10635/17356
Title: Spin-Orbit Interaction Induced Spin-Separation In Platinum Nanostructures
Authors: KOONG CHEE WENG
Keywords: Spin Hall effect, Platinum, spin-orbit interaction, spin transport, nanoscale device,
Issue Date: 4-Sep-2009
Source: KOONG CHEE WENG (2009-09-04). Spin-Orbit Interaction Induced Spin-Separation In Platinum Nanostructures. ScholarBank@NUS Repository.
Abstract: We have demonstrated electrical generation and detection of spin polarization by the spin Hall effect in platinum. The spin Hall effect refers to the generation of a transverse spin current, and the subsequent non-equilibrium spin accumulation near sample boundaries. This occurs when a longitudinal electrical current is applied to materials with spin-orbit interaction. Spin polarization in metals is usually small and requires ferromagnetic metals to create and detect spin polarization. This ferromagnetic-based approach is suitable to be used as a laboratory investigation of spin transport phenomenon, but it limits the performance and scalability of the spintronics devices. Therefore, we designed and experimentally demonstrated using a non-local lateral geometry structure to investigate the generation and detection of spin polarization based on the spin Hall effect, without the need for magnetic materials, external magnetic field, or bulky optical systems. The geometry made use of the spin Hall effect effect to generate spin polarization and its reciprocal effect, the inverse spin Hall effect, to detect spin polarization. A large spin Hall effect signal was observed from 10 K up to room temperature, which was the largest value reported so far in the literature. The measurements were also done using gold and aluminum samples. Aluminum failed to demonstrate any signal while gold showed weak signals compared to platinum in spite of similar atomic number. This suggested that the spin Hall effect in platinum was unusual. The drift-diffusion model was found to be adequate to model the spin transport in platinum. Based on the experimental results, the spin Hall effect in platinum was expected to be extrinsic. However, the extrinsic contribution to the observed effect was not fully understood and further investigation is needed.
URI: http://scholarbank.nus.edu.sg/handle/10635/17356
Appears in Collections:Ph.D Theses (Open)

Show full item record
Files in This Item:
File Description SizeFormatAccess SettingsVersion 
KoongCW.pdf9.67 MBAdobe PDF

OPEN

NoneView/Download
Appendix B.pdf823.1 kBAdobe PDF

OPEN

NoneView/Download
Appendix C.pdf284.67 kBAdobe PDF

OPEN

NoneView/Download

Page view(s)

340
checked on Dec 11, 2017

Download(s)

647
checked on Dec 11, 2017

Google ScholarTM

Check


Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.