"Modulating the spin polarization of photoelectrons from a topological insulator"

Who: Cheol-Hwan Park (Seoul National University, Korea)

Place: Auditorium of the Centro de Fisica de Materiales, Paseo Manuel de Lardizabal 5, Donostia-San Sebastián

Date: Friday, 5 August 2016, 12:00

Modulating the spin polarization of photoelectrons from a topological insulator

Cheol-Hwan Park, Seoul National University
(Host at CFM: Ivo Souza)


After a theoretical study [1] predicted that the spin polarization of
photoelectrons emitted from a topological insulator is highly tunable such
that almost 100 % polarization along any arbitrary direction can be
achieved by tuning the polarization of light, a number of experimental
confirmations of this photo-induced spin modulation phenomenon followed
[2-6].  This photo-induced spin modulation phenomenon
involving topological insulators suggests a new kind of spin-polarized
electron sources [2]; however, there are some experimental results that
cannot be explained by previous theoretical descriptions [1]. In this
presentation, I will review these experimental results [2,4] and our
interpretation [7].

[1] C.-H. Park, S. G. Louie, Phys. Rev. Lett. 109, 097601 (2012).
[2] C. Jozwiak et al., Nat. Phys. 9, 293 (2013).
[3] Z.-H. Zhu et al., Phys. Rev. Lett. 112, 076802 (2014).
[4] Z. Xie et al., Nat. Commun. 5, 3382 (2014).
[5] Y. Cao et al., arXiv:1211.5998v1
[6] J. Sánchez-Barriga et al., Phys. Rev. X 4, 011046 (2014).
[7] J. H. Ryoo and C.-H. Park, Phys. Rev. B, 93, 085419 (2016).

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