Details
| Original language | English |
|---|---|
| Article number | 045201 |
| Journal | Physical Review B |
| Volume | 96 |
| Issue number | 4 |
| Publication status | Published - 5 Jul 2017 |
Abstract
We combine extensive precision measurements of the optically detected spin dynamics and magneto-transport measurements in a contiguous set of n-doped bulk GaAs structures, in order to unambiguously unravel the intriguing but complex contributions to the spin relaxation at the metal-to-insulator transition (MIT). Just below the MIT, the interplay between hopping induced loss of spin coherence and hyperfine interaction yields a maximum spin lifetime exceeding 800 ns. At slightly higher doping concentrations, however, the spin relaxation deviates from the expected Dyakonov-Perel mechanism which is consistently explained by a reduction of the effective motional narrowing close to the MIT. The reduction is attributed to the change of the dominant momentum scattering mechanism in the metallic impurity band, where scattering by local conductivity domain boundaries due to the intrinsic random distribution of donors becomes significant. Here, we fully identify and model all intricate contributions of the relevant microscopic scattering mechanisms, which allows the complete quantitative modeling of the electron spin relaxation in the entire regime from weakly interacting up to fully delocalized electrons.
ASJC Scopus subject areas
- Materials Science(all)
- Electronic, Optical and Magnetic Materials
- Physics and Astronomy(all)
- Condensed Matter Physics
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In: Physical Review B, Vol. 96, No. 4, 045201, 05.07.2017.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - Closing the gap between spatial and spin dynamics of electrons at the metal-to-insulator transition
AU - Lonnemann, J. G.
AU - Rugeramigabo, E. P.
AU - Oestreich, M.
AU - Hübner, J.
N1 - Funding information: We acknowledge the financial support by the BMBF joint research project Q.com-H (16KIS0109 and 16KIS00107) and the Deutsche Forschungsgemeinschaft (OE 177/10-1) as well as from the NTH School for Contacts in Nanosystems.
PY - 2017/7/5
Y1 - 2017/7/5
N2 - We combine extensive precision measurements of the optically detected spin dynamics and magneto-transport measurements in a contiguous set of n-doped bulk GaAs structures, in order to unambiguously unravel the intriguing but complex contributions to the spin relaxation at the metal-to-insulator transition (MIT). Just below the MIT, the interplay between hopping induced loss of spin coherence and hyperfine interaction yields a maximum spin lifetime exceeding 800 ns. At slightly higher doping concentrations, however, the spin relaxation deviates from the expected Dyakonov-Perel mechanism which is consistently explained by a reduction of the effective motional narrowing close to the MIT. The reduction is attributed to the change of the dominant momentum scattering mechanism in the metallic impurity band, where scattering by local conductivity domain boundaries due to the intrinsic random distribution of donors becomes significant. Here, we fully identify and model all intricate contributions of the relevant microscopic scattering mechanisms, which allows the complete quantitative modeling of the electron spin relaxation in the entire regime from weakly interacting up to fully delocalized electrons.
AB - We combine extensive precision measurements of the optically detected spin dynamics and magneto-transport measurements in a contiguous set of n-doped bulk GaAs structures, in order to unambiguously unravel the intriguing but complex contributions to the spin relaxation at the metal-to-insulator transition (MIT). Just below the MIT, the interplay between hopping induced loss of spin coherence and hyperfine interaction yields a maximum spin lifetime exceeding 800 ns. At slightly higher doping concentrations, however, the spin relaxation deviates from the expected Dyakonov-Perel mechanism which is consistently explained by a reduction of the effective motional narrowing close to the MIT. The reduction is attributed to the change of the dominant momentum scattering mechanism in the metallic impurity band, where scattering by local conductivity domain boundaries due to the intrinsic random distribution of donors becomes significant. Here, we fully identify and model all intricate contributions of the relevant microscopic scattering mechanisms, which allows the complete quantitative modeling of the electron spin relaxation in the entire regime from weakly interacting up to fully delocalized electrons.
UR - http://www.scopus.com/inward/record.url?scp=85026378472&partnerID=8YFLogxK
U2 - 10.1103/PhysRevB.96.045201
DO - 10.1103/PhysRevB.96.045201
M3 - Article
AN - SCOPUS:85026378472
VL - 96
JO - Physical Review B
JF - Physical Review B
SN - 2469-9950
IS - 4
M1 - 045201
ER -