Announcing the summer trimester: Spin systems and phases of matter
Kick-off event at the Institut Henri Poincaré on Wednesday 04/06/2025. Infos and registration: https://indico.math.cnrs.fr/e/sspm
Observable-projected ensemble
bySara Murciano
Abstract:Local measurements in many‐body quantum systems can produce surprising phenomena—from preparing long‐range entangled states to driving measurement‐induced phase transitions and modifying critical behavior. In this talk, I will introduce a new “observable‐projected” protocol: rather than performing complete projective measurements on the complement of a subsystem, we measure a single, local Hermitian operator on part of that complement. The result is a mixed‐state ensemble on the subsystem that remains analytically tractable within a conformal field theory framework. I will then show how this ensemble’s entanglement structure can be computed, and present a detailed case study of the free compact boson.