Large, Room Temperature Photocurrents in WSM TaAs*

Numerous predictions exist for novel photocurrent generation related to the novel topology of inversion breaking Weyl semi-metals. We present here the first observation of room temperature, polarization controlled, photocurrents in mesoscale TaAs devices. From their qualitatively different polarization and frequency dependencies we are able to disentangle these from more mundane thermal effects. The magnitude of the photocurrents is consistent with reports of an intrinsically large second order optical response in TaAs, due to the unique band topology. Furthermore, these results suggest TaAs could be a promising material for optoelectronic and photovoltaic applications.