Press Releases

2016.07.22

Zero-bias photocurrent in ferromagnetic topological insulator : Professor Masashi Kawasaki, Professor Yoshinori Tokura, Department of Applied Physics, and other researchers.

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.

 

Nature Communications URL : http://www.nature.com/ncomms/2016/160720/ncomms12246/full/ncomms12246.html