Details
| Original language | English |
|---|---|
| Article number | 235205 |
| Number of pages | 7 |
| Journal | Physical Review B |
| Volume | 102 |
| Issue number | 23 |
| Publication status | Published - 21 Dec 2020 |
Abstract
We investigate the strong field nuclear spin relaxation rate in n-type GaAs for doping densities from the quasi-insulating over the metal-to-insulator up to the quasimetallic regime. The rate measured at 6.5 K increases in the quasi-insulating regime with doping density due to nuclear spin diffusion to the donor electrons and shows a distinct maximum at the critical density of the Mott metal-to-insulator transition. The density dependence of the nuclear spin relaxation rate can be quantitatively calculated over the whole density regime taking into account the effective number of localized electrons and the interaction of free electrons via the Korringa mechanism. Only the nuclear spin relaxation rate of the very lowest doped sample shows a significant deviation from these calculations. Temperature-dependent measurements suggest in this case an additional nuclear spin relaxation channel which is negligible at higher doping densities and is linked to the electron spin relaxation time.
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. 102, No. 23, 235205, 21.12.2020.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - Doping and temperature dependence of nuclear spin relaxation in n-type GaAs
AU - Abaspour, L.
AU - Sterin, P.
AU - Rugeramigabo, E. P.
AU - Hübner, J.
AU - Oestreich, M.
N1 - Funding Information: We thank J. G. Lonnemann for support concerning the experimental method. This work was funded by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) under Germany's Excellence Strategy-EXC-2123 QuantumFrontiers-390837967, research training group 1991, and OE 177/10-2, and the NTH School for Contacts in Nanosystems.
PY - 2020/12/21
Y1 - 2020/12/21
N2 - We investigate the strong field nuclear spin relaxation rate in n-type GaAs for doping densities from the quasi-insulating over the metal-to-insulator up to the quasimetallic regime. The rate measured at 6.5 K increases in the quasi-insulating regime with doping density due to nuclear spin diffusion to the donor electrons and shows a distinct maximum at the critical density of the Mott metal-to-insulator transition. The density dependence of the nuclear spin relaxation rate can be quantitatively calculated over the whole density regime taking into account the effective number of localized electrons and the interaction of free electrons via the Korringa mechanism. Only the nuclear spin relaxation rate of the very lowest doped sample shows a significant deviation from these calculations. Temperature-dependent measurements suggest in this case an additional nuclear spin relaxation channel which is negligible at higher doping densities and is linked to the electron spin relaxation time.
AB - We investigate the strong field nuclear spin relaxation rate in n-type GaAs for doping densities from the quasi-insulating over the metal-to-insulator up to the quasimetallic regime. The rate measured at 6.5 K increases in the quasi-insulating regime with doping density due to nuclear spin diffusion to the donor electrons and shows a distinct maximum at the critical density of the Mott metal-to-insulator transition. The density dependence of the nuclear spin relaxation rate can be quantitatively calculated over the whole density regime taking into account the effective number of localized electrons and the interaction of free electrons via the Korringa mechanism. Only the nuclear spin relaxation rate of the very lowest doped sample shows a significant deviation from these calculations. Temperature-dependent measurements suggest in this case an additional nuclear spin relaxation channel which is negligible at higher doping densities and is linked to the electron spin relaxation time.
UR - http://www.scopus.com/inward/record.url?scp=85099159619&partnerID=8YFLogxK
U2 - 10.1103/PhysRevB.102.235205
DO - 10.1103/PhysRevB.102.235205
M3 - Article
AN - SCOPUS:85099159619
VL - 102
JO - Physical Review B
JF - Physical Review B
SN - 2469-9950
IS - 23
M1 - 235205
ER -