NICOP - Robust electronic excitations in nanostructures induced by topological states of light
Abstract
The early 90 witnessed a breakthrough in optics with the discovery of techniques togenerate coherent beams of light having phase singularities and carrying orbital angularmomentum (OAM), called optical vortices (OV) or twisted light. The original discoveryspread quickly into several areas of fundamental and applied physics, and has become amain subject of study. With a 2007 Editor~s Choice article in EPL, collaborators and Ipioneered the subject of solid-state ~ OV interaction; since then we have studied basicprinciples in bulk and nanostructures and explored potential applications tonanotechnology, quantum information and spintronics.Topological insulators, topological protection, quantum Hall effect, and topologicalquantum computing with anyons are nowadays active and very successful areas ofresearch, signaling the importance of applying topology to physics. Topology focuses onspaces, describing global structures and transformations that preserves them. Twoadditional subjects, Index Theory and Nonlinear Dynamics, tackle global properties ofvector fields and their critical points. Ideas and tools from topology, index theory andnon-linear dynamics fit perfectly in the realm of OV physics. Nonetheless, it appears thatno attempt has been made so far to analyze from that perspective the OV-solidinteraction.We recently identified two distinct classes of OV, with important quantitative andqualitative features; we called them parallel and antiparallel because of the relativeorientation of spin and orbital angular momenta. Due the their global features, they mayimprint on matter topologically-distinct electronic states (excitons) on semiconductores.Following general considerations on index theory, non-linear dynamics and topology weexpect these topologically-distinct excitation to be robust under dephasing/decayprocesses. The expectation is partially supported by work in exciton-polariton physicsthat points to the existence of topologically-distinct robust vortex states (not induced bytwisted light), and by independent experiments on unexpected long exciton lifetimes inbulk semiconductors induced by OV.In this project we will investigate the transfer of global features of OV to quantum dotsand quantum rings. The former is by far the most well-studied nanosystem, and it hasbeen proposed many times as a candidate for a variety of applications. On the otherhand, for symmetry reasons is the QR the closest to OV; therefore, it is what we wouldcall the archetypical system to study the optical excitation by OV. Using theoretical andnumerical methods we will investigate questions such as the following: Will parallel andanti-parallel OV imprint globally distinguishable polarizations in the medium and thusproduce topologically-distinct electronic states in semiconductor nanostructures? Does aphysical analysis in terms of electron-electron and electron-phonon interactions supportthe mathematical expectation that parallel and antiparallel electronic states are robustunder local perturbation? Can we make use of these robust electronic states in improveproposals to quantum information technology?
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Jul 10, 2018
- Source ID
- N629091812090
Entities
People
- Guillermo F. Quinteiro
Organizations
- Office of Naval Research
- United States Navy