Far-field excitation of single graphene plasmon cavities with ultracompressed mode volumes

Acoustic graphene plasmons are highly confined electromagnetic modes carrying large momentum and low loss in the mid-infrared and terahertz spectra. However, until now they have been restricted to micrometer-scale areas, reducing their confinement potential by several orders of magnitude. Using a graphene-based magnetic resonator, we realized single, nanometer-scale acoustic graphene plasmon cavities, reaching mode volume confinement factors of ~5 x 1010. Such a cavity acts as a mid-infrared nanoantenna, which is efficiently excited from the far field and is electrically tunable over an extremely large broadband spectrum. Our approach provides a platform for studying ultrastrong-coupling phenomena, such as chemical manipulation via vibrational strong coupling, as well as a path to efficient detectors and sensors operating in this long-wavelength spectral range.

Source: ScienceNOW - June 10, 2020 Category: Science Authors: Epstein, I., Alcaraz, D., Huang, Z., Pusapati, V.-V., Hugonin, J.-P., Kumar, A., Deputy, X. M., Khodkov, T., Rappoport, T. G., Hong, J.-Y., Peres, N. M. R., Kong, J., Smith, D. R., Koppens, F. H. L. Tags: Physics reports Source Type: news