English

Extracting higher central charge from a single wave function

Strongly Correlated Electrons 2024-01-08 v4 High Energy Physics - Theory Quantum Physics

Abstract

A (2+1)D topologically ordered phase may or may not have a gappable edge, even if its chiral central charge cc_- is vanishing. Recently, it is discovered that a quantity regarded as a "higher" version of chiral central charge gives a further obstruction beyond cc_- to gapping out the edge. In this Letter, we show that the higher central charges can be characterized by the expectation value of the \textit{partial rotation} operator acting on the wavefunction of the topologically ordered state. This allows us to extract the higher central charge from a single wavefunction, which can be evaluated on a quantum computer. Our characterization of the higher central charge is analytically derived from the modular properties of edge conformal field theory, as well as the numerical results with the ν=1/2\nu=1/2 bosonic Laughlin state and the non-Abelian gapped phase of the Kitaev honeycomb model, which corresponds to U(1)2\mathrm{U}(1)_2 and Ising topological order respectively. The letter establishes a numerical method to obtain a set of obstructions to the gappable edge of (2+1)D bosonic topological order beyond cc_-, which enables us to completely determine if a (2+1)D bosonic Abelian topological order has a gappable edge or not. We also point out that the expectation values of the partial rotation on a single wavefunction put a constraint on the low-energy spectrum of the bulk-boundary system of (2+1)D bosonic topological order, reminiscent of the Lieb-Schultz-Mattis type theorems.

Keywords

Cite

@article{arxiv.2303.04822,
  title  = {Extracting higher central charge from a single wave function},
  author = {Ryohei Kobayashi and Taige Wang and Tomohiro Soejima and Roger S. K. Mong and Shinsei Ryu},
  journal= {arXiv preprint arXiv:2303.04822},
  year   = {2024}
}

Comments

21 pages, 13 figures. v4: added numerical simulations for the non-chiral \nu=2/3 FQH state. Accepted in Physical Review Letters

R2 v1 2026-06-28T09:08:04.866Z