ITAMP Lunch Seminar

Speaker: Thomas Christensen (MIT)

Date: Thursday, April 19th

Time: 12:00-1:00 pm

Includes Pizza.

Title: Non-conventional surface and edge effects in plasmonics

Abstract: I will discuss some recent work, which exemplify aspects of plasmonics that broadly fall under the category of non-conventional electronic and optical interface effects. Quantum corrections in nanoplasmonics [1] exemplifies the former aspect; for structural feature-sizes or resonant wavelengths approaching the few-nanometer regime, the conventional, local description of electromagnetics breaks down due to its omission of electronic spill-out, surface-enabled Landau damping, and nonlocality. In noble metals, a hydrodynamic model provides a decent effective remedy to the conventional approach, e.g. reproducing experimentally measured blueshifts and regularizing several singular limits of the conventional approach. Though popular and physically transparent, however, the hydrodynamic model is not a generic remedy due to its neglect of spill-out and surface-enabled Landau damping. I will discuss how a recently developed framework, based on the so-called Feibelman d-parameters, allows an general, analytical, and straightforward account of all surface-related corrections with TDDFT-level accuracy.  

Finally, I will discuss our recent work on the prediction of high-frequency topological plasmonic edge modes in structured graphene under a magnetic bias [2] as well as the experimental measurement of low-frequency topological magnetoplasmonic edge modes in the 2D electron gas of a hetero-junction.