Open AccessZero-bias photocurrent in ferromagnetic topological insulator
Author(s) -
Norio Ogawa,
Ryutaro Yoshimi,
K. Yasuda,
Atsushi Tsukazaki,
Masashi Kawasaki,
Y. Tokura
Publication year - 2016
Publication title -
nature communications
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.559
H-Index - 365
ISSN - 2041-1723
DOI - 10.1038/ncomms12246
Subject(s) - physics , topological insulator , photocurrent , dirac (video compression format) , photoexcitation , electron , condensed matter physics , topology (electrical circuits) , position and momentum space , zero point energy , quantum mechanics , excitation , mathematics , combinatorics , neutrino
Magnetic interactions in topological insulators cause essential modifications in the originally mass-less surface states. They offer a mass gap at the Dirac point and/or largely deform the energy dispersion, providing a new path towards exotic physics and applications to realize dissipation-less electronics. The nonequilibrium electron dynamics at these modified Dirac states unveil additional functions, such as highly efficient photon to spin-current conversion. Here we demonstrate the generation of large zero-bias photocurrent in magnetic topological insulator thin films on mid-infrared photoexcitation, pointing to the controllable band asymmetry in the momentum space. The photocurrent spectra with a maximal response to the intra-Dirac-band excitations can be a sensitive measure for the correlation between Dirac electrons and magnetic moments.