Vectorial spin polarization detection in multichannel spin-resolved photoemission spectroscopy using an Ir(001) imaging spin filter

Abstract

We report on spin-and angular-resolved photoemission spectroscopy using a high-resolution imaging spin filter based on a large Ir(001) crystal enhancing the effective figure of merit for spin detection by a factor of over 10 3 compared to standard single-channel detectors. Furthermore, we review the spin filter preparation and its lifetime. The spin filter efficiency is mapped on a broad range of scattering energies and azimuthal angles. Large spin filter efficiencies are observed for the spin component perpendicular as well as parallel to the scattering plane depending on the azimuthal orientation of the spin filter crystal. A spin rotator capable of manipulating the spin direction prior to detection complements the measurement of three observables, thus allowing for a derivation of all three components of the spin polarization vector in multichannel spin polarimetry. The experimental results nicely agree with spin-polarized low-energy electron diffraction calculations based on a fully relativistic multiple scattering method in the framework of spin-polarized density functional theory.

Spin-resolved inelastic electron scattering by spin waves in noncollinear magnets

“…For magnetic transition metals, spinorbit coupling is much weaker than the exchange scattering, which is why such scattering processes can be ignored. On heavy metals, spin-orbit coupling becomes important, e.g., allowing a full spin characterization of flying electrons by surface skew scattering [54]. This could be used as a spin filter in SREELS, but it might also require a high intensity electron beam to compensate for the low efficiency of the spin detection.…”

Multidimensional photoemission spectroscopy—the space-charge limit

“…Combined with an imaging spin filter, the ToF-approach allows us to measure data arrays of one spin component P (E B , k x , k y ); in the future even all three components [21]. Existing imaging spin filters are not yet fully optimised; however first results look very promising [22,23].…”

Spin- and time-resolved photoelectron spectroscopy and diffraction studies using time-of-flight momentum microscopes

“…The vector P can be composed by its Cartesian components P x , y , z or alternatively parametrized by the underlying mechanisms as P M (in ferromagnets), P Fano , P Mott , P Rashba or P long (longitudinal spin component appearing for Rashba systems with high Z), depending on the properties of the electronic system. Vectorial measurements can be implemented exploiting symmetry properties of the spinfilter material 105 or by spin rotators. 243 More details on the structure of P and the relation between atomic and solid-state photoemission are discussed in the review by Heinzmann and Dil.…”

“…The spin filter integrated into a ToF-MM consists of the second ToF branch (90°-branch, DLD 2) and the retractable spinfilter crystal. Several types of spin-filter crystals have been characterized and used, [101][102][103][104][105] more are proposed. 106,107 A spin-and angle-resolved (spin-ARPES) spectrometer with a Co film as a spin filter coupled with a laboratory-based UV laser has been developed by the Berkeley group.…”