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We have investigated the electronic states and spin polarization of half-metallic ferromagnet CrO 2 (100) epitaxial films by bulk-sensitive spin-resolved photoemission spectroscopy with a focus on non-quasiparticle (NQP) states derived from electron-magnon interactions. We found that the averaged values of the spin polarization are approximately 100% and 40% at 40 K and 300 K, respectively. This is consistent with the previously reported result [H. Fujiwara et al., Appl. Phys. Lett. 106 , 202404 (2015).]. At 100 K, peculiar spin depolarization was observed at the Fermi level ( E F ), which is supported by theoretical calculations predicting NQP states. This suggests the possible appearance of NQP states in CrO 2 . We also compare the temperature dependence of our spin polarizations with that of the magnetization. [ABSTRACT FROM AUTHOR]

A novel design of high-voltage compatible polarimeter for spin-resolved hard X-ray photoelectron spectroscopy (Spin-HAXPES) went into operation at beamline BL09XU of SPring-8 in Hyogo, Japan. The detector is based on the well-established principle of electron diffraction from a W(001) single-crystal at a scattering energy of 103.5 eV. It's special feature is that it can be operated at a high negative bias potential up to 10 kV, necessary to access the HAXPES range. The polarimeter is operated behind a large hemispherical analyzer (Scienta R-4000). It was optimized for high transmission of the transfer optics. A delay-line detector (20 mm dia.) is positioned at the exit plane of the analyzer enabling conventional multichannel intensity spectroscopy simultaneously with single-channel spin analysis. The performance of the combined setup is demonstrated by the spin-resolved data for the valence-region of a FeCo functional layer of a tunneling device, buried beneath 3 nm of oxidic material. The well-structured spin polarization spectrum validates Spin-HAXPES in the valence energy range as powerful method for bulk electronic structure analysis. The spin polarization spectrum exhibits a rich structure, originating from clearly discernible transitions in the majority and minority partial spin spectra. [ABSTRACT FROM AUTHOR]

We report high-resolution spin- and angle-resolved photoemission spectroscopy of bismuth thin film on Si(1 1 1) to discuss the spin structure of surface states. We found that, unlike conventional picture of the Rashba splitting, the magnitude of the in-plane spin polarization is asymmetric between two hole pockets across the Brillouin-zone center. In addition, these pockets exhibit a giant out-of-plane spin polarization as large as the in-plane counterpart, which changes the sign across the Γ ¯     M ¯ line. We also revealed that the spin polarization of the Rashba surface states near the Brillouin-zone boundary (the M ¯ point) is gradually reduced on decreasing the film thickness. Our result provides a new pathway to generate and control spin-polarized electrons in the Rashba system. [ABSTRACT FROM AUTHOR]

Abstract: The spin- and angle-resolved photoelectron spectroscopy from ultrathin Cr films on Fe(110) is investigated by means of first-principles electronic structure and photoemission calculations. The antiferromagnetic ordering in the Cr films leads in dependence on film thickness to a rapidly decreasing and oscillating photoelectron spin polarization, in reasonable agreement with recent experiments (Dedkov (2007) ). The oscillation period is explained by quantum-well states in the Cr film and by a Fermi surface nesting vector. The importance of transition matrix elements is highlighted. The findings point to a noncollinear magnetic structure at the Fe/Cr interface. [ABSTRACT FROM AUTHOR]

Vanadium diselenide (VSe 2) is a van der Waals layered transitional metal dichalcogenide, which has attracted intensive attention due to the coexistence of charge density wave (CDW) transition and magnetic property down to two-dimension limit. We apply Spin- and angle-resolved photoemission spectroscopy measurement to explore the evolution of the valence eletronic states of VSe 2 accompanied with the CDW transition. The V 3 d -derived-band in the vicinity of Fermi energy shows negligible spin polarization both below and above the CDW transition temperature. Furthermore, a sizable spin polarization of Se 4 p electronic states has been clearly observed, indicating an atomic-layer-dependent spin polarization in VSe 2. Our results provide new clues to understand the spin polarized electronic states in transitional metal dichalcogenides. [ABSTRACT FROM AUTHOR]