  We demonstrate experimentally that Tamm plasmons in the near-IR can be
supported by a dielectric mirror interfaced with a metasurface, a discontinuous
thin metal film periodically patterned on the sub-wavelength scale. More
crucially, not only do Tamm plasmons survive the nano-patterning of the metal
film, but they also become sensitive to external perturbations, as a result. In
particular, by depositing a nematic liquid crystal on the outer side of the
metasurface we were able to red-shift the spectral position of Tamm plasmon by
35 nm, while electrical switching of the liquid crystal enabled us to tune the
wavelength of this notoriously inert excitation within a 10 nm range.
