Science Daily  June 10, 2024 Recent theoretical studies have suggested that transition metal perovskite oxide membranes can enable surface phonon polaritons in the infrared range with low loss and much stronger subwavelength confinement than bulk crystals. Such modes, however, have not been experimentally observed so far. An international team of researchers (USA – North Carolina State University, Lawrence Berkeley National Laboratory, Stanford University, SLAC National Accelerator Laboratory, Switzerland) studied the phonon polaritons in a 100 nm thick freestanding crystalline membrane of SrTiO3 transferred on metallic and dielectric substrates. They observed a symmetric-antisymmetric mode splitting which gave rise to epsilon-near-zero and Berreman […]