Related Experiment Video
Updated: Jun 1, 2026

Scalable Quantum Integrated Circuits on Superconducting Two-Dimensional Electron Gas Platform
Published on: August 2, 2019
Entanglement of low-energy excitations in conformal field theory
Francisco Castilho Alcaraz1, Miguel Ibáñez Berganza, Germán Sierra
1Instituto de Física de São Carlos, Universidade de São Paulo, Caixa Postal 369, São Carlos, SP, Brazil.
Abstract:
In a quantum critical chain, the scaling regime of the energy and momentum of the ground state and low-lying excitations are described by conformal field theory (CFT). The same holds true for the von Neumann and Rényi entropies of the ground state, which display a universal logarithmic behavior depending on the central charge. In this Letter we generalize this result to those excited states of the chain that correspond to primary fields in CFT. It is shown that the nth Rényi entropy is related to a 2n-point correlator of primary fields. We verify this statement for the critical XX and XXZ chains. This result uncovers a new link between quantum information theory and CFT.
Related Concept Videos
Divergence and Curl of Electric Field
Atomic Nuclei: Nuclear Relaxation Processes
Electrostatic Boundary Conditions
The surface integral of an electric field is given by Gauss's law in integral form and is related to...
Equipotential Surfaces and Field Lines
Energy Associated With a Charge Distribution
Region of Convergence of Laplace Tarnsform
Consider a decaying exponential signal that begins at a specific time. When deriving its Laplace transform, the time-domain variable is replaced with a complex variable. This substitution...

