DCMPMS Seminars

SYNTHETIC DIMENSIONS: HARNESSING INTERNAL DEGREES OF FREEDOM OF LIGHT FOR QUANTUM AND TOPOLOGICAL PHOTONICS

by Dr. Avik Dutt (Stanford University)

Friday, April 16, 2021 from to (Asia/Kolkata)
at Online through ZOOM Webinar(Zoom link: ( https://us02web.zoom.us/j/86220048712?pwd=U2N4L1FlU3QvTFRzZ0VQbFhxT3NIUT09 )
Description
The dimensionality of a physical system strongly influences its
properties. Moreover, richer topological features typically arise with
increasing dimensionality, which necessitate complicated
high-dimensional spatial structures. Recently, “synthetic dimensions”
have emerged to circumvent the challenge of realizing such 0 
high-dimensional structures, by replacing one or more spatial dimensions
with intrinsic properties of photons such as frequency, spin or temporal
modes. Synthetic dimensions enable very simple photonic structures to be
used for classical and quantum simulation of high-dimensional physics,
complementing the recent surge in studying low-dimensional physics in
quantum materials, 2D materials and cold atoms.

In this talk, I will discuss how dynamically modulated photonic cavities
provide a fertile ground to realize synthetic dimensions and demonstrate
complex topological effects. We introduce and demonstrate a
synthetic-dimension spectroscopy technique to directly read out band
structures from a time-resolved transmission. Using this technique, we
probed 2D quantum Hall physics in a single cavity by simultaneously
harnessing two synthetic dimensions of frequency and spin, thus
elucidating how higher-dimensional physics can be implemented in
simpler, experimentally feasible lower-dimensional structures. In such a
cavity, neutral photons experience an artificial magnetic field,
allowing us to observe a wide variety of phenomena such as spin-orbit
coupling, spin-momentum locking, chiral edge currents and a
Meissner-to-vortex phase transition at room temperature. Examples of the
extreme tunability of synthetic-space photonic circuits to realize
flexibly reprogrammable long-range complex coupling and reconfigurable
lattice Hamiltonians will also be provided, in a manner that is
challenging in real-space architectures. The talk will conclude with
prospects for studying new phases of light and matter such as
higher-order topological insulators and non-Hermitian phases, and also
provide an outlook for using such concepts for quantum and nanophotonic
technologies.