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arXiv · 2411.10244

Entanglement asymmetry in CFT with boundary symmetry breaking

Michele Fossati·Colin Rylands·Pasquale Calabrese
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Abstract

We examine the behavior of the entanglement asymmetry in the ground state of a (1+1)-dimensional conformal field theory with a boundary condition that explicitly breaks a bulk symmetry. Our focus is on the asymmetry of a subsystem $A$ originating from the symmetry-breaking boundary and extending into a semi-infinite bulk. By employing the twist field formalism, we derive a universal expression for the asymmetry, showing that the asymptotic behavior for large subsystems is approached algebraically, with an exponent which is twice the conformal dimension of a boundary condition-changing operator. As a secondary result, we also establish a similar asymptotic behavior for the string order parameter. Our exact analytical findings are validated through numerical simulations in the critical Ising and 3-state Potts models.

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Michele Fossati, Colin Rylands, Pasquale Calabrese. 2024-11-15. Entanglement asymmetry in CFT with boundary symmetry breaking. https://arxiv.org/abs/2411.10244

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