Stephen Bartlett, The University of Sydney
Quantum information is very fragile, but clever quantum engineers aspire to use error correction to keep information intact. Topologically ordered phases—wherein the most exotic properties of quantum physics such as entanglement are protected within a strongly-interacting material—are currently being commandeered as quantum error-correcting codes for today’s quantum architectures. I’ll introduce these as well as a new generation of theoretical materials that promise to self-correct themselves. Much like a real-world example of Schrödinger’s Cat, a self-correcting quantum memory can protect quantum information in a thermal environment for an arbitrarily long time, without the need for active error correction. I’ll demonstrate that symmetry can assist in giving self-correction in 3D spin lattice models. In particular, I’ll present quantum codes corresponding to a 2D symmetry-enriched topological (SET) phase that appears naturally on the boundary of an exotic 3D symmetry-protected topological (SPT) phase.
Colloquium at 2:30 with reception at 2:00.