Pure Spin Currents

“Body Pure spin currents transfer intrinsic angular momentum (spin) without a net transfer of charge. Photons can transfer angular momentum from a circularly polarised beam to electrons in GaAs, for example, and excite spin-polarised electrons. A current of these electrons is spin-polarised but it also transfers charge so it is not a pure spin current. Here we are referring to electrons that transfer spin without transferring charge. In this talk I will describe experiments to generate pure spin currents, reveal their properties and show how they can be manipulated. In particular, I will discuss the intriguing questions, ‘if a pure spin current does not convey charge, is it therefore dissipationless’ and ‘are pure spin currents useful’?”