Image of Dynamic Local Exchange Interactions in the dc Magnetoresistance of Spin-Polarized Current through a Dopant.

Autor:	McMillan SR; Optical Science and Technology Center, and Department of Physics and Astronomy, University of Iowa, Iowa City, Iowa 52242, USA.; Pritzker School of Molecular Engineering, University of Chicago, Chicago, Illinois 60637, USA., Harmon NJ; Optical Science and Technology Center, and Department of Physics and Astronomy, University of Iowa, Iowa City, Iowa 52242, USA., Flatté ME; Optical Science and Technology Center, and Department of Physics and Astronomy, University of Iowa, Iowa City, Iowa 52242, USA.; Pritzker School of Molecular Engineering, University of Chicago, Chicago, Illinois 60637, USA.; Department of Applied Physics, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven, Netherlands.
Jazyk:	angličtina
Zdroj:	Physical review letters [Phys Rev Lett] 2020 Dec 18; Vol. 125 (25), pp. 257203.
DOI:	10.1103/PhysRevLett.125.257203
Abstrakt:	We predict strong, dynamical effects in the dc magnetoresistance of current flowing from a spin-polarized electrical contact through a magnetic dopant in a nonmagnetic host. Using the stochastic Liouville formalism we calculate clearly defined resonances in the dc magnetoresistance when the applied magnetic field matches the exchange interaction with a nearby spin. At these resonances spin precession in the applied magnetic field is canceled by spin evolution in the exchange field, preserving a dynamic bottleneck for spin transport through the dopant. Similar features emerge when the dopant spin is coupled to nearby nuclei through the hyperfine interaction. These features provide a precise means of measuring exchange or hyperfine couplings between localized spins near a surface using spin-polarized scanning tunneling microscopy, without any ac electric or magnetic fields, even when the exchange or hyperfine energy is orders of magnitude smaller than the thermal energy.
Databáze:	MEDLINE
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