Electrical control of spin transport is promising for achieving new device functionalities. Here we calculate the propagation of spin currents in a graphene-based spin-current demultiplexer under the effect of drift currents. We show that, using spin- and charge-transport parameters already obtained in experiments, the spin currents can be guided in a controlled way. In particular, spin-current selectivities up to ${10}^2$ can be achieved for measurements over a distance of $10\mu \mathrm{m}$ under a moderate drift current density of $20\mu \mathrm{A}/\mu \mathrm{m}$, meaning that the spin current in the arm that is off is only 1% of the current in the arm that is on. To illustrate the versatility of this approach, we show similar efficiencies in a device with four outputs and the possibility of multiplexer operation using spin drift. Finally, we explain how the effect can be optimized in graphene and two-dimensional semiconductors.

• Received 8 June 2018
• Revised 19 August 2018

DOI:https://doi.org/10.1103/PhysRevApplied.10.044073