Quantum codes, lattices, and CFTs

PIRSA ID: 20110066
Série : Perimeter Institute Quantum Discussions, Quantum Fields and Strings
Event Type: Seminar
Domaine(s) scientifique(s) :
Quantum Fields and Strings
 ,
Quantum Information
Date de fin :
Speaker(s):
  • Anatoly Dymarsky, Skolkovo Institute of Science and Technology
November 25, 2020 at 11:00 AM Other/External

There is a deep relation between classical error-correcting codes, Euclidean lattices, and chiral 2d CFTs. We show this relation
extends to include quantum codes, Lorentzian lattices, and non-chiral CFTs. The relation to quantum codes provides a simple way to solve
modular bootstrap constraints and identify interesting examples of conformal theories. In particular we construct many examples of physically distinct isospectral theories, examples of "would-be" CFT partition function -- non-holomorphic functions satisfying all constraints of the modular bootstrap, yet not associated with any

known CFT, and find theory with the maximal spectral gap among all Narain CFTs with the central charge c=4. At the level of code theories the problem of finding maximal spectral gap reduces to the problem of finding optimal code, leading to "baby bootstrap" program. We also discuss averaging over the ensemble of all CFTs associated with quantum codes, and its possible holographic interpretation. The talk is based on arXiv:2009.01236 and arXiv:2009.01244.