Detection of spin current by electron spin resonance

We propose an electrical scheme for detection of pure spin current without charge current by electron spin resonance (ESR). The pure spin current is flowing through a two-dimensional electron gas (2DEG) heterojunction consisting of two 2DEG electrodes with Rashba and/or Dresselhaus spin orbital interaction and a nonmagnetic narrow strip between them. When an ESR is introduced in the system, the interplay between ESR and spin current will lead to a nonzero charge current flowing due to breakdown of dynamic time reverse symmetry of the system. The induced charge current, not only its magnitude but also its direction, can be modulated by system parameters such as ESR frequency and gate voltage, because spin current itself fulfills the electron-hole inversion antisymmetry. Our proposal to use ESR pumping charge current may pave a new way to detect electrically pure spin current. © 2008 American Institute of Physics.