Luttinger liquid plasmons in single walled carbon nanotubes*

Plasmons, collective excitations of electrons, hold immense promise for advancing nanoscale photonics and electronics integration. Despite their advantages, progress towards plasmonic circuits has been impeded by difficulties in achieving robust spatial confinement, low dispersion, and a high quality-factor. Luttinger liquid theory, a theory of strongly interacting 1D electrons, predicts a variety of physical phenomena starkly different from the Fermi liquid model of non-interacting electrons. Among these are the collective excitations of strongly interacting electrons, called Luttinger liquid plasmons (LLPs). These LLPs exhibit a high quality-factor, strong spatial confinement, and low dispersion, all highly desirable characteristics for achieving nanophotonic circuits. While LLPs in single-walled carbon nanotubes (SWCNTs) hold great promise as a foundation for nanoscale plasmonic circuits as demonstrated by Shi, Wang et al., Nature Photonics 9, 515–519 (2015), a comprehensive examination of their temperature, energy and substrate dependence is still absent. We present our preliminary scanning near-field optical microscopy data of the temperature and substrate dependence of LLPs in SWCNTs.