Spinresolved Electron Spectroscopy and Microscopy

Based on classical designs of spin detectors, like the high-energy Mott detector [1] and the SPLEED-detector exploiting the (2,0) diffraction spot from W(100) [2] we continue spin detector development and employ spin-resolved spectroscopy for various purposes. In particular, a multichannel approach has been introduced, which improves the performance by orders of magnitude [3]. This mode will be especially useful for low intensity experiments like spin-resolved hard X-ray photoelectron spectroscopy (learn more Spin-HAXPES), where the first experiment has just been performed successfully [4].

 

Figure 1: Sketch of the imaging spin filter for the idealized case of a parallel beam.

 

This novel ansatz is based on the fact that the conservation of k-parallel in the specular beam allows to transfer a complete image via the scattering process (see Fig.1). Behind a hemispherical electron spectrometer the novel learn more multichannel spin detector extends the approach of parallel detection of an energy and angle interval to spin-resolved spectroscopy [5,6]. Implemented into the column of a PEEM or momentum microscope, the learn more imaging spin filter yields high magnetic contrast (domain contrast) that can also be combined with spectro microscopy [7]. The latter development is performed in cooperation with the Max-Planck-Institute for Micro Structure Physics (Prof. Kirschner, Dr. Tusche).

We also apply an alternative method of spin-filtering by implementing an learn more electron-transparent ultrathin ferromagnetic foil as spin-selective absorber into the column of a PEEM. Spin-dependent transmission is characterized by very high spin selectivity [8]. The novel approaches will facilitate experiments that are impossible given the performance of present single-channel spin polarimeters.

 

References:

[1] G. Schönhense, Phys. Rev. Lett. 44, 640 (1980)
[2] J. Kirscher and R. Feder, Phys. Rev. Lett. 42, 1008 (1979)
[3] German patent DE 2005 045 622 B4
[4] G. Stryganyuk, X. Kozina, G. H. Fecher, S. Ouardi, S. Chadov, C. Felser, G. Schoenhense, A. Oelsner, P. Bernhard, E. Ikenaga, T. Sugiyama, H. Sukegawa, Z. Wen, K. Inomata, and K. Kobayashi, Spin Polarimetry and Magnetic Dichroism on a buried magnetic layer using Hard X-ray Photoelectron Spectroscopy, Jpn. J. Appl. Phys. (2012) Jpn. J. Appl. Phys. 51 016602.
[5] M. Kolbe, P. Lushchyk, B. Petereit, H.-J. Elmers, G. Schoenhense, A. Oelsner, C. Tusche, and J. Kirschner, Highly efficient multichannel spin detection, Phys. Rev. Lett. (2011), Phys. Rev. Lett. 107 (2011) 207601
[6] M. Hahn G. Schönhense, E. Arbelo Jorge and M. Jourdan, Significant spin polarization of Co2MnGa Heusler thin films on MgO (100) measured by ultraviolet photoemission spectroscopy, Appl. Phys. Lett. 98 (2011) 232503-3
[7] C. Tusche, M. Ellguth, A. A. Ünal, C. T. Chiang, A. Winkelmann, A. Krasyuk, M. Hahn, G. Schönhense, J. Kirschner
Spin resolved photoelectron microscopy using a two-dimensional spin-polarizing electron mirror, Appl. Phys. Lett. 99, 032505 (2011)
[8] G. Schönhense, H. C. Siegmann, Transmission of electrons through ferromagnetic material and applications to detection of electron spin polarization, Ann. Phys. 2, 465 (1993)

 

 


 

Last update: Tuesday, 24-Sep-2013 11:07:31 CEST Email D. Panzer Impressum