Abstract

Coupling between plasmonic nano-components generates strongly red-shifted resonances combined with intense local field amplification on the nanoscale. In recent years we have explored plasmonic coupling combined with soft materials to tune this interaction dynamically, and to work in the strong coupling domain for gaps below 1nm which can be formed reliably by bottom-up self-assembly. At these distances, coupled dipoles are not sufficient to describe the response, and the system is described in terms of gap plasmons. The crucial aspect of these systems is the extreme sensitivity to separation, and how quantum tunnelling starts to play an influence that can be directly seen at room temperature in ambient conditions. We recently demonstrated how quantum plasmonics controls the very smallest space that light can be squeezed into. We now show how graphene is the smallest possible spacer of 0.3nm in a plasmonic dimer, and allows active tuning of the plasmonic modes.

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