24–25 sept. 2026
Institut Henri Poincaré
Fuseau horaire Europe/Paris

Entanglement at Quantum Criticality

24 sept. 2026, 14:45
45m
Amphithéatre Hermite (Institut Henri Poincaré)

Amphithéatre Hermite

Institut Henri Poincaré

11 Rue Pierre et Marie Curie, 75005 Paris

Orateur

Benoit Estienne (LPTHE, Sorbonne Université)

Description

Over the past twenty years, quantum entanglement has established itself as a central theme of research across a wide spectrum of physics, from high-energy theory to condensed matter and quantum information. In the context of this talk, the key point is that entanglement measures have proven to be a remarkably powerful tool for investigating the physics of one-dimensional quantum critical systems.

I will begin by introducing the relevant concepts and reviewing the replica approach to computing Rényi entropies. For one-dimensional quantum systems in particular, the entanglement entropy can be evaluated within two complementary frameworks. In the geometric perspective, the scaling limit reduces the problem to computing a partition function on a branched covering of certain Riemann surfaces—effectively a replication of space-time. In contrast, the algebraic perspective replicates the degrees of freedom themselves, leading to the formulation of a cyclic orbifold.

Following this review, I will highlight the main obstacles to evaluating entanglement entropies in one-dimensional quantum critical systems, and outline some recent developments.

Documents de présentation