Accessing the fundamentals of magnetotransport in metals with terahertz probes
authors Jin, ZM; Tkach, A; Casper, F; Spetter, V; Grimm, H; Thomas, A; Kampfrath, T; Bonn, M; Klaui, M; Turchinovich, D
nationality International
journal NATURE PHYSICS
keywords LAYERED MAGNETIC-STRUCTURES; GIANT MAGNETORESISTANCE; FERROMAGNETIC NICKEL; SPIN DYNAMICS; ENERGY-BANDS; TRANSPORT; DEMAGNETIZATION; SPECTROSCOPY; TEMPERATURE; RELAXATION
abstract Spin-dependent conduction in metals underlies all modern magnetic memory technologies, such as giant magnetoresistance (GMR). The charge current in ferromagnetic transition metals is carried by two non-mixing populations of sp-band Fermi-level electrons: one of majority-spin and one of minority-spin. These electrons experience spin-dependent momentum scattering with localized electrons, which originate from the spin-split d-band. The direct observation of magnetotransport under such fundamental conditions, however, requires magnetotransport measurements on the same timescale as the electron momentum scattering, which takes place in the sub-100 fs regime. Using terahertz electromagnetic probes, we directly observe the magnetotransport in a metallic system under the fundamental conditions, and determine the spin-dependent densities and momentum scattering times of conduction electrons. We show that traditional measurements significantly underestimate the spin asymmetry in electron scattering, a key parameter responsible for effects such as GMR. Furthermore, we demonstrate the possibility of magnetic modulation of terahertz waves, along with heat- and contact-free GMR readout using ultrafast terahertz signals.
publisher NATURE PUBLISHING GROUP
issn 1745-2473
year published 2015
volume 11
issue 9
beginning page 761
ending page 766
digital object identifier (doi) 10.1038/NPHYS3384
web of science category Physics, Multidisciplinary
subject category Physics
unique article identifier WOS:000360709200021
  ciceco authors
  impact metrics
times cited (wos core): 27
journal impact factor (jcr 2016): 22.806
5 year journal impact factor (jcr 2016): 22.684
category normalized journal impact factor percentile (jcr 2016): 98.101
altmetrics:



 


Events
Sponsors

1suponsers_list_ciceco.jpg