Fig. 5

Excitation power and temperature dependence of the E ₁₁ exciton emission linewidth. a Spectral linewidth determined from Voigt deconvolution fits (Supplementarty Note 7) as a function of laser excitation power (780 nm) for a plasmonically coupled SWCNT (red squares) and reference SWCNT (blue circles). The blue box highlights the pump regime when the linewidths reaches the Purcell-enhanced radiative lifetime limit of the emitter (T ₁ = 37 ps = 18 µeV). Gray dashed line illustrates spectral resolution limit (23 µeV). The red box highlights the pump regime where plasmonic heating affects the emission spectrum. Data are recorded at 3.8 K. b PL spectra for the coupled SWCNT recorded in the plasmonic heating regime where a significant lattice temperature increase causes the break-up of the acoutic-phonon confinement leading to strong linewidth broadening. c Comparision spectra for the coupled SWCNT recorded under moderate pump powers of 200 μW and for increasing temperature from 20 to 130 K. d FDTD simuation of temperature raise ΔT of the bowtie structure as a function of excitation power (blue dots). Inset: Simulated heat map of the bowtie antenna. The red stars are the data points from the experiements in b with the temperature equivalent taken from the experiment in c