Lattice realization of complex CFTs: Two-dimensional Potts model
with Q > 4 states
Kay Jörg Wiese, Jesper Lykke Jacobsen
CNRS-Laboratoire de Physique de
l'Ecole Normale Supérieure, ENS, Université PSL, CNRS, Sorbonne Universités, Université Paris-Diderot, Sorbonne Paris Cité
24 rue Lhomond, 75005 Paris, France
Abstract
The two-dimensional $Q$-state Potts model with real couplings has a first-order transition for $Q>4$.
We study a loop-model realization in which $Q$ is a continuous
parameter. This model allows for the collision of a critical and a
tricritical fixed point at $Q=4$, which then emerge as complex
conformally invariant theories at $Q>4$, or even complex $Q$, for
suitable complex coupling constants. All critical exponents can be obtained as analytic continuation of known exact results for $Q \le 4$. We verify this scenario in detail for $Q=5$ using transfer-matrix computations.
arXiv:2402.10732 [pdf]
Phys. Rev. Lett. 133 (2024) 077101 [pdf]
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by Kay Wiese. Last edited Feb. 17, 2024.