Research

Past projects include topological phenomena in plasmonics systems (PRL & Nat. Commun.). More recent projects include analysis of band connectivity and topology in 3D photonic crystals (PRX), topology-optimization of photonic crystals (arXiv), and quasicrystalline Weyl points (arXiv).

Many of my more recent activities have been associated with development of symmetry-based methods. Several of the associated software tools are available as open-source software, implemented in the Julia programming language:

• Crystalline.jl: Space group theory, including complete irrep tables, subgroup relations, band representations, and group listings.

• Brilllouin.jl: High-symmetry paths in k-space for band structure calculation.

• KdotP.jl: Symmetry-constrained derivation of k⋅p models in crystals.

• Neumann.jl: Symmetry-allowed components of a response tensor.

For more examples of open-source software, see my Github profile.

At sufficiently small scales, on the order a few nanometers, the classical description of plasmonics breaks down and quantum mechanical effects become non-negligible. Building upon work by Feibelman from the 70s and 80s, we introduced a new framework centered around surface response functions to incorporate effects like electron spill-out, nonlocality, and surface-assisted Landau damping (PRL and Nature). The tools have since found applications to questions in light-matter interaction (Nat. Commun.) and acoustic graphene plasmons (Nat. Commun.).

With collaborators in Prof. Soljačić's group, we've explored the application of neural networks to photonic crystals (Nanophotonics); more recently, we used photonic crystals as a testbed for exploring novel approaches to transfer learning in science (Nat. Commun.).