Nonlinear detection of spin currents in graphene with non-magnetic electrodes

Nature Physics (Impact Factor: 20.6). 04/2012; 8(4). DOI: 10.1038/nphys2219
Source: arXiv

ABSTRACT The abilities to inject and detect spin carriers are fundamental for
research on transport and manipulation of spin information. Pure
electronic spin currents have been recently studied in nanoscale
electronic devices using a non-local lateral geometry, both in metallic
systems and in semiconductors. To unlock the full potential of
spintronics we must understand the interactions of spin with other
degrees of freedom. Such interactions have been explored recently, for
example, by using spin Hall or spin thermoelectric effects. Here we
present the detection of non-local spin signals using non-magnetic
detectors, through an as-yet-unexplored nonlinear interaction between
spin and charge. In analogy to the Seebeck effect, where a heat current
generates a charge potential, we demonstrate that a spin current in a
paramagnet leads to a charge potential, if the conductivity is energy
dependent. We use graphene as a model system to study this effect, as
recently proposed. The physical concept demonstrated here is generally
valid, opening new possibilities for spintronics.

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