Probing magnetic exchange interactions with helium
Abstract
Controlling and sensing spin-polarization of electrons forms the basis of spintronics. Here, we report a study of the effect of helium on the spin-polarization of the tunneling current and magnetic contrast in spin-polarized Scanning Tunneling Microscopy. We show that the magnetic contrast in SP-STM images recorded in the presence of helium depends sensitively on the tunneling conditions. From tunneling spectra and their variation across the atomic lattice we establish that the helium can be reversibly ejected from the tunneling junction by the tunneling electrons. The energy of the tunneling electrons required to eject the helium depends on the relative spin-polarization of the tip and sample, making the microscope sensitive to the magnetic exchange interactions. We show that the time-averaged spin polarization of the tunneling current is suppressed in the presence of helium and thereby demonstrate voltage control of the spin polarization of the tunneling current across the tip-sample junction.
Citation
Trainer , C , Yim , C M , Heil , C , Farrar , L , Tsurkan , V , Loidl , A & Wahl , P 2021 , ' Probing magnetic exchange interactions with helium ' , Physical Review Letters , vol. 127 , no. 16 , 166803 . https://doi.org/10.1103/PhysRevLett.127.166803
Publication
Physical Review Letters
Status
Peer reviewed
ISSN
0031-9007Type
Journal article
Description
Funding: CT and PW acknowledge support from EPSRC (EP/R031924/1) and CMY and LSF from EP/S005005/1. C.H. acknowledges support by the Austrian Science Fund (FWF) Project No. P32144-N36 and the VSC-4 of the Vienna University of Technology. The work was partially supported by the Deutsche Forschungsgemeinschaft (DFG) through Transregional Research Collaboration TRR 80 (Augsburg, Munich, and Stuttgart).Collections
Items in the St Andrews Research Repository are protected by copyright, with all rights reserved, unless otherwise indicated.