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Title: Tuning spin dynamics and localization near the metal-insulator transition in Fe/GaAs heterostructures

Abstract

We present a simultaneous investigation of coherent spin dynamics in both localized and itinerant carriers in Fe/GaAs heterostructures using ultrafast and spin-resolved pump-probe spectroscopy. We find that for excitation densities that push the transient Fermi energy of photocarriers above the mobility edge there exist two distinct precession frequencies in the observed spin dynamics, allowing us to simultaneously monitor both localized and itinerant states. For low magnetic fields (below 3.00 T) the beat frequency between these two excitations evolves linearly, indicating that the nuclear polarization is saturated almost immediately and that the hyperfine coupling to these two states is comparable, despite the 20 times enhancement in nuclear polarization provided by the presence of the Fe layer. At higher magnetic fields (above 3.00 T) the Zeeman energy drives reentrant localization of the photocarriers. Subtracting the constant hyperfine contribution from both sets of data allows us to extract the Lande g factor for each state and estimate their energy relative to the bottom of the conduction band, yielding -2.16 and 17 meV for localized and itinerant states, respectively. This work advances our fundamental understanding of spin-spin interactions between electron and nuclear spin species, as well as between localized and itinerant electronic states, andmore » therefore has implications for future work in both spintronics and quantum information/computation.« less

Authors:
 [1];  [2];  [3];  [4];  [2];  [1]
  1. The Ohio State Univ., Columbus, OH (United States)
  2. Univ. of Iowa, Iowa City, IA (United States)
  3. Univ. of California, Riverside, CA (United States)
  4. The Ohio State Univ., Columbus, OH (United States); Univ. of California, Riverside, CA (United States)
Publication Date:
Research Org.:
The Ohio State Univ., Columbus, OH (United States)
Sponsoring Org.:
USDOE Office of Science (SC), Basic Energy Sciences (BES)
OSTI Identifier:
1480653
Alternate Identifier(s):
OSTI ID: 1478687
Grant/Contract Number:  
FG02-03ER46054; SC0001304
Resource Type:
Journal Article: Accepted Manuscript
Journal Name:
Physical Review B
Additional Journal Information:
Journal Volume: 98; Journal Issue: 13; Journal ID: ISSN 2469-9950
Publisher:
American Physical Society (APS)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; Spin; spintronics; magnetism; semiconductor; hyperfine; coherent; ultrafast

Citation Formats

Ou, Yu-Sheng, Harmon, N. J., Odenthal, Patrick, Kawakami, R. K., Flatté, M. E., and Johnston-Halperin, E. Tuning spin dynamics and localization near the metal-insulator transition in Fe/GaAs heterostructures. United States: N. p., 2018. Web. doi:10.1103/PhysRevB.98.134444.
Ou, Yu-Sheng, Harmon, N. J., Odenthal, Patrick, Kawakami, R. K., Flatté, M. E., & Johnston-Halperin, E. Tuning spin dynamics and localization near the metal-insulator transition in Fe/GaAs heterostructures. United States. https://doi.org/10.1103/PhysRevB.98.134444
Ou, Yu-Sheng, Harmon, N. J., Odenthal, Patrick, Kawakami, R. K., Flatté, M. E., and Johnston-Halperin, E. 2018. "Tuning spin dynamics and localization near the metal-insulator transition in Fe/GaAs heterostructures". United States. https://doi.org/10.1103/PhysRevB.98.134444. https://www.osti.gov/servlets/purl/1480653.
@article{osti_1480653,
title = {Tuning spin dynamics and localization near the metal-insulator transition in Fe/GaAs heterostructures},
author = {Ou, Yu-Sheng and Harmon, N. J. and Odenthal, Patrick and Kawakami, R. K. and Flatté, M. E. and Johnston-Halperin, E.},
abstractNote = {We present a simultaneous investigation of coherent spin dynamics in both localized and itinerant carriers in Fe/GaAs heterostructures using ultrafast and spin-resolved pump-probe spectroscopy. We find that for excitation densities that push the transient Fermi energy of photocarriers above the mobility edge there exist two distinct precession frequencies in the observed spin dynamics, allowing us to simultaneously monitor both localized and itinerant states. For low magnetic fields (below 3.00 T) the beat frequency between these two excitations evolves linearly, indicating that the nuclear polarization is saturated almost immediately and that the hyperfine coupling to these two states is comparable, despite the 20 times enhancement in nuclear polarization provided by the presence of the Fe layer. At higher magnetic fields (above 3.00 T) the Zeeman energy drives reentrant localization of the photocarriers. Subtracting the constant hyperfine contribution from both sets of data allows us to extract the Lande g factor for each state and estimate their energy relative to the bottom of the conduction band, yielding -2.16 and 17 meV for localized and itinerant states, respectively. This work advances our fundamental understanding of spin-spin interactions between electron and nuclear spin species, as well as between localized and itinerant electronic states, and therefore has implications for future work in both spintronics and quantum information/computation.},
doi = {10.1103/PhysRevB.98.134444},
url = {https://www.osti.gov/biblio/1480653}, journal = {Physical Review B},
issn = {2469-9950},
number = 13,
volume = 98,
place = {United States},
year = {Wed Oct 24 00:00:00 EDT 2018},
month = {Wed Oct 24 00:00:00 EDT 2018}
}

Journal Article:

Figures / Tables:

FIG. 1 FIG. 1: (a) Schematic of time-resolved Faraday rotation (TRFR) measurement geometry. (b) Measured Faraday rotation ($$θ$$FR) vs $$Δ$$t for a Fe/MgO/GaAs heterostructure (solid circles) and a control GaAs epilayer (open circles) at $$T$$= 5 K and $$B$$app= 0.10 T. The data are offset for clarity. (c) Top panel: total fieldmore » $$B$$tot (Larmor frequency $$f$$) as a function of $$B$$app between +0.80 T and -0.80 T at $$T$$ = 5K. Bottom panel: nuclear field $$B$$$$n$$ ( $$B$$$$n$$= $$B$$tot – $$B$$app) as a function of $$B$$app.« less

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Works referenced in this record:

A silicon-based nuclear spin quantum computer
journal, May 1998


Graphene spintronics
journal, October 2014


Electron-spin relaxation in bulk GaAs for doping densities close to the metal-to-insulator transition
journal, February 2010


A single-atom electron spin qubit in silicon
journal, September 2012


Electronic measurement and control of spin transport in silicon
journal, May 2007


Theory of electron spin relaxation in n -doped quantum wells
journal, February 2010


ESR linewidth behavior for barely metallic n -type silicon
journal, October 1987


Electrical detection of spin transport in lateral ferromagnet–semiconductor devices
journal, February 2007


Quantum computing with defects
journal, April 2010


Ferromagnetic Imprinting of Nuclear Spins in Semiconductors
journal, October 2001


Resonant Spin Amplification in n -Type GaAs
journal, May 1998


Tuning the dynamic exchange interaction in ferromagnet/semiconductor heterostructures
conference, September 2015


Coherent Dynamics of Coupled Electron and Nuclear Spin Qubits in Diamond
journal, October 2006


Electron-nuclei spin coupling in GaAs—Free versus localized electrons
journal, March 2012


A study of the conduction band non-parabolicity, anisotropy and spin splitting in GaAs and InP
journal, September 1987


Theory of optical orientation in n -type semiconductors
journal, September 2004


Electron spin dynamics in cubic GaN
journal, December 2016


Room temperature coherent control of defect spin qubits in silicon carbide
journal, November 2011


Spin coherence and dephasing in GaN
journal, March 2001


Manipulation of Spin Transport in Graphene by Surface Chemical Doping
journal, May 2010


All-Optical Magnetic Resonance in Semiconductors
journal, January 2000


Inversion of Ferromagnetic Proximity Polarization by MgO Interlayers
journal, June 2008


Spontaneous spin coherence in n -GaAs produced by ferromagnetic proximity polarization
journal, March 2002


Exchange-Driven Spin Relaxation in Ferromagnet-Oxide-Semiconductor Heterostructures
journal, March 2016


Fabrication of sub-transistor via holes for small and efficient power amplifiers using highly selective GaAs∕InGaP wet etching
journal, January 2006

  • Uchiyama, Hiroyuki; Ohta, Hiroshi; Shiota, Takashi
  • Journal of Vacuum Science & Technology B: Microelectronics and Nanometer Structures, Vol. 24, Issue 2
  • https://doi.org/10.1116/1.2178368

Figures/Tables have been extracted from DOE-funded journal article accepted manuscripts.