Anomalous transport of quasiparticles in non-Hermitian systems
Lecturer: Himadri Tanaya Sahoo - Tata Institute of Fundamental Research Mumbai, India
Date: Oct. 24, 2022 2 p.m. - 4 p.m.
Location: Querzoli
Organizer: Wiersma Diederik
Non-Hermitian transport of quasiparticles has garnered immense interest due to its rich physics and potential applications. The introduction of disorders into an otherwise periodic template leads to exponential attenuation of waves as a consequence of multiple scattering. Here, we present a different transport regime manifested due to the coexistence of non-Hermiticity and disorder. We experimentally confirm such an anomalous transport regime of hybrid quasiparticles in a 1D array of metal grooves known as Spoof Surface PlasmonPolariton structures (SSPPs) designed for microwave frequencies. We introduce randomness in the spatial position of each groove. Non-Hermiticity is induced due to inherent metallic dissipation. The polariton-plasmon hybridization leads to eigenvalue condensation, which results in transport through multiple localized resonances known as necklace states.  The anomalous transport regime opens up in the vicinity of the hybridization frequency as a consequence of frequency-pinning of the migrating modes.