The Hall Effects Edwin Hall Never Imagined
CIC nanoGUNE Seminars
- Speaker
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Xiaofeng Jin, Fudan University
- When
-
2019/06/14
13:00 - Place
- nanoGUNE seminar room, Tolosa Hiribidea 76, Donostia - San Sebastian
- Add to calendar
-
iCal
The anomalous Hall effect (AHE) is one of the oldest and most prominent
transport phenomena in magnetic materials. However, the microscopic mechanism
of the AHE has remained unresolved for
more than a century because its rich phenomenology defies standard
classification, prompting conflicting claims of the dominant processess. We
differentiate these processes through temperature-dependent measurements on
epitaxial Fe, Ni, Co, and NixCu1-x films of varying thickness [1], [2]. The
results allow an unambiguous identification of both intrinsic and extrinsic
mechanisms of the anomalous Hall effect. The more recently discovered spin
Hall effect (SHE) has attracted a great deal of attention because of its
potential applications in spin current devices. Various methods have been
developed to generate and detect the SHE and search for materials with large
spin Hall angles. These efforts notwithstanding, reliable and accurate
determination of spin Hall angle remains a challenge. In this lecture I will
first give a comprehensive discussion on the basic concepts of AHE and SHE.
Expoliting the attributes of epitaxial magnetic thin films, I will then
explain how to control independenly the different scattering processes through
temperature and layer thickness and to identifiy unambiguously the intrinsic
and extrinsic mechanisms of the AHE. Finally, based on the understanding of
the microscopic mechanisms of the AHE, I will describe how we developed a new
method using H-patterned films to measure quantities inherent in the SHE.
[1] Y. Tian, L. Ye, and X, Jin, “Proper scaling of the anomalous Hall
effect,†Phys. Rev. Lett. 103, 087206 (2009), doi :
10.1103/PhysRevLett.103.087206.
[2] D.-Z. Hou, G. Su, Y. Tian, X. Jin, S. A. Yang, and Q. Niu, Phys. Rev.
Lett. 114, 217203 (2015), doi: 10.1103/PhysRevLett.114.217203.
**Biography**
Xiaofeng Jin received the B.S. and Ph.D. degrees in physics from Fudan
University in 1983 and 1989, respectively. Concurrently, he was at Laboratoire
pour l’Utilisation du Rayonnement Electromagnetique (LURE) in Orsay, France,
from June 1987 to May 1988. He joined the faculty at the Department of
Physics, Fudan University, in 1989, and became full professor in 1995. He has
been a visiting scholar at many research institutes including University of
California, Berkeley; Chalmers University of Technology, Goteborg; Max-Planck
Institute for Microstructure, Halle; University of Utah; Institute for
Materials Research, Tohoku University, Sendai; and Hong Kong University of
Science and Technology. He has published over 100 technical articles in peer-
reviewed journals, including book chapters and review articles, and has given
more than 50 invited presentations at international conferences. He served as
the chair of the 21st International Colloquium on Magnetic Films and Surfaces
(ICMFS) in 2012 and on the advisary committes and program committees of
various international conferences on magnetism and spintronics. He is
currently the chair of the International Union of Pure and Applied Physics
(IUPAP) Magnetism Commission C9. He is a member of the IEEE Magnetics Society.
**Host** : F. Casanova