Research
Dynamical Response of Electron Gas
We are very excited about our recent work with collaborators at U. Mass. Amherst has been publish in PRL as an editor's suggestion.
Algorithmic Matsubara Integration
We are very excited about our recent work with PhD student Amir Taheridehkordi published in PRB in which we solve high dimensional integrals analytically using a computational algorithm. This new method for tackling Feynman diagrammatics resolves a number of major roadblocks to the field. Particularly how to avoid numerical analytic continuation.
Benchmarking the 2D Hubbard Model
As part of the Simons Collaboration on the Many Electron Problem, we produced numerical benchmarks of the Hubbard model in two-dimensions, published in PRX.
Phenomenology of the Pseudogap
Understanding the pseudogap is a longstanding problem in the field of high temperature superconductivity in the cuprate materials. The pseudogap appears as a partial suppression of states near to the Fermi level in only one region of momentum space. From a phenomenological viewpoint, there exist numerous mean-field calculations which can give rise to pseudogap features. However, there has yet to be a definitive consensus as to the source of the pseudogap in the cuprates specifically.
One particularly successful model proposed by Yang, Rice and Zhang (YRZ) has allowed us, and others, to describe the basic behaviour of experimentally measurable quantities, such as specific heat, penetration depth, optical in-plane and c-axis conductivities, and Raman spectroscopy. This work was recently reviewed by Rice et al.. The review can be found on the arXiv.
Plasmonics in 2D Dirac systems
The isolation of single layers of carbon atoms in 2005 by Novoselov and Geim leads us to study the correlations in graphene, and other reduced dimensional materials which exhibit 2D Dirac cones. This includes graphene under strain, as well as hexagonal warping present in the band structure of surface states in a topological insulator. Of particular interest are the interactions which cause plasmons, charge density oscillations, in a system to couple to electrons producing new quasiparticle peaks called plasmarons. These plasmarons have been observed in graphene on various passivated substrates.
Unparticle Mediated Superconductivity
Unparticles, first proposed by Georgi in 2006, represent a possible new form of scale invariant matter. If unparticles could exist in condensed matter systems they might couple to charge degrees of freedom, while not contributing to quasiparticle densities. Recently we explored the repercussions of such scale invariant matter and find the existence of anomalous solutions to the mean-field BCS equations for cooper pairs mediated by the unparticle generalization of the Coulomb interaction. Our recent paper on the arXiv, 'Unparticle Mediated Superconductivity', in collaboration with Adolfo Grushin at MPI-PKS, was the topic of some serious blogging by Mr. Kentucky F.C., so check it out here!
