Előadó: Németh Gergely (SZFI)
Előadás címe: Real-space observation of ultrastrong coupling between carbon nanotube plasmons and substrate phonons
Dátum: 2022. április 26., 10:00
Helyszín: 1-es épület Tanácsterem, illetve online: https://wigner-hu.zoom.us/j/86517517678?pwd=WWVhSE1KMzhWa20zWWw1Z0ZlL3J… Meeting ID: 865 1751 7678 Passcode: 650334
Összefoglaló:
Strong and ultrastrong coupling (SC and USC) between light and matter creates a plethora of new possibilities like induced transparency, polariton lasing, changing of the rate of chemical reactions, or enhanced sensitivity in infrared and Raman spectroscopy. However, the strong coupling is very challenging to achieve in the mid-infrared spectral range due to the low oscillator strengths of molecular vibrations and long wavelengths. The recently visualized Luttinger-liquid plasmons in carbon nanotubes feature very long plasmonic lifetimes and extreme field localization making them ideal candidates to realize strong or even ultrastrong coupling at infrared frequencies. We applied scanning near-field polariton interferometry to examine the interaction between propagating Luttinger-liquid plasmons in individual carbon nanotubes and surface phonon polaritons of silica and hexagonal boron nitride. We extracted the dispersion relation of the hybrid Luttinger-liquid plasmon–phonon polaritons (LPPhPs) and explained the observed phenomena by the classical coupled harmonic oscillator model. The dispersion shows pronounced mode splitting, and the obtained value for the normalized coupling strength shows that we reached the ultrastrong coupling regime with both native silica and hBN phonons. Our findings predict future applications to exploit the extraordinary properties of carbon nanotube plasmons, ranging from nanoscale plasmonic circuits to ultrasensitive molecular sensing.
