Photonic anomalous quantum hall effect
Orre, Venkata Vikram
Chong, Yi Dong
Date of Issue2019
School of Physical and Mathematical Sciences
Centre for Disruptive Photonic Technologies
We experimentally realize a photonic analogue of the anomalous quantum Hall insulator using a two-dimensional (2D) array of coupled ring resonators. Similar to the Haldane model, our 2D array is translation invariant, has a zero net gauge flux threading the lattice, and exploits next-nearest neighbor couplings to achieve a topologically nontrivial band gap. Using direct imaging and on-chip transmission measurements, we show that the band gap hosts topologically robust edge states. We demonstrate a topological phase transition to a conventional insulator by frequency detuning the ring resonators and thereby breaking the inversion symmetry of the lattice. Furthermore, the clockwise or the counterclockwise circulation of photons in the ring resonators constitutes a pseudospin degree of freedom. The two pseudospins acquire opposite hopping phases, and their respective edge states propagate in opposite directions. These results are promising for the development of robust reconfigurable integrated nanophotonic devices for applications in classical and quantum information processing.
Optical & Microwave Phenomena
Physical Review Letters
© 2019 American Physical Society. All rights reserved. This paper was published in Physical Review Letters and is made available with permission of American Physical Society.