30 Jan
2019
30 Jan
'19
9:59 a.m.
Harvard Quantum Initiative Special Seminar
Wednesday, January 30
10:00 AM
Jefferson 356
Nathan Schine (University of Chicago)
Quantum Hall physics with photons
Topological materials have recently become a distinct focus in condensed matter physics,
appearing famously in the quantum Hall effect and topological insulators. In these
materials, certain essential properties are governed by ‘topological invariants,’
quantities insensitive to local perturbation or manipulation. As such, understanding and
measuring topological invariants play a central role in investigations of topological
materials.
Synthetic materials in which the constituent particles are photons trapped in an optical
resonator offer an exciting platform on which to study topological materials. Recent
efforts have realized broad control over the single-photon Hamiltonian, including a strong
synthetic magnetic field for photons, and strong photon-photon interactions. In this talk,
I will present how a nonplanar resonator can harbor a quantum Hall system on the surface
of a cone. I will then discuss measurements of three distinct topological indices,
offering insight onto their physical meaning and application. We measure the Chern number
via local real-space projectors and access two additional topological invariants, the mean
orbital spin and chiral central charge, via the variation of the local density of states
near a singularity of spatial curvature. I will then transition to the creation of strong
interactions between individual photons by hybridizing cavity photons with Rydberg
excitations of a cold atomic gas. Combining these technologies enables our ongoing work
towards the creation of a fractional quantum Hall system of photons and the corresponding
exploration of correlated states and topological phases of matter.
Clare Ploucha
Administrative Program Manager
Max Planck/Harvard Research Center for Quantum Optics
Department of Physics
17 Oxford Street, Jefferson 357
Cambridge, MA 02138
P: 617-495-3388