Fig. 2: Plasmonic reflectances obtained by removing both the sapphire phonon contributions below −1000 cm−1 and the high-frequency background above −7000 cm−1.
From: Infrared plasmons in ultrahigh conductive PdCoO2 metallic oxide
Plasmon absorption hardens by decreasing width W and periodicity 2W, i.e. by increasing the corresponding wavevector q = π/W as expected from theory.
