Spin States in Bismuth and Its Surfaces: Hyperfine Interaction.
Degree: PhD, Physics, 2021, Virginia Tech
This dissertation focuses on the heavy element bismuth (Bi), a semimetal with strong spin-orbit interaction at its two-dimensional surface. Given the challenge to grow high qualityBi(111) films, we present an optimized van der Waals epitaxy technique to grow Bi(111)films on mica substrates, which show a flat surface with large grain sizes and a layered step height of 0.391±0.015 nm, corresponding to one Bi(111) bilayer height. To demonstrate the high quality of the Bi(111) surface, a comparison of surface morphology was conducted among Bi(111) films deposited on three different substrates (mica, Si(111), and InSb(111)B),along with a comparison between their electronic transport properties. By applying a DC current on the high quality Bi(111) film on mica, a carrier spin polarization is established via mainly what we here call the Edelstein effect, which then induces dynamic nuclear polarization by hyperfine interaction and generates a non-equilibrium nuclear spin polarization without externally applied magnetic field. We quantified the Overhauser field from the nuclear polarization all-electrically by conducting quantum transport antilocalization experiments, which showed a suppression of antilocalization by the in-plane Overhauser field.Comparative measurements indicated that the magnitude of the Overhauser field depends onthe spin-polarizing DC current magnitude and the polarization duration. The experiments also show that antilocalization forms a sensitive probe for hyperfine interaction and nuclear polarization.
Advisors/Committee Members: Heremans, Jean Joseph (committeechair), Soghomonian, Victoria Garabed (committee member), Park, Kyungwha (committee member), Emori, Satoru (committee member).
Subjects/Keywords: bismuth; mica; Si(111); hyperfine interaction; Edelstein effect; nuclear spin polarization; Overhauser field; weak antilocalization.
to Zotero / EndNote / Reference
APA (6th Edition):
Jiang, Z. (2021). Spin States in Bismuth and Its Surfaces: Hyperfine Interaction. (Doctoral Dissertation). Virginia Tech. Retrieved from http://hdl.handle.net/10919/101787
Chicago Manual of Style (16th Edition):
Jiang, Zijian. “Spin States in Bismuth and Its Surfaces: Hyperfine Interaction.” 2021. Doctoral Dissertation, Virginia Tech. Accessed March 01, 2021.
MLA Handbook (7th Edition):
Jiang, Zijian. “Spin States in Bismuth and Its Surfaces: Hyperfine Interaction.” 2021. Web. 01 Mar 2021.
Jiang Z. Spin States in Bismuth and Its Surfaces: Hyperfine Interaction. [Internet] [Doctoral dissertation]. Virginia Tech; 2021. [cited 2021 Mar 01].
Available from: http://hdl.handle.net/10919/101787.
Council of Science Editors:
Jiang Z. Spin States in Bismuth and Its Surfaces: Hyperfine Interaction. [Doctoral Dissertation]. Virginia Tech; 2021. Available from: http://hdl.handle.net/10919/101787