ETD

• Boundary Quantum Field Theory
• Conformal Field Theory
• Defects
• Entanglement
• Many-body theory
• Quantum wires

The study of entanglement measures is of interest in various fields of physics. Entanglement entropy and negativity are computable using field theoretical techniques, providing a meeting point between many-body and high energy physics. This work studies such measures in extended one-dimensional systems with defects or junctions.

The focus is on critical systems, where CFT techniques can be used, and defects which do not break criticality. Universal results are obtained using Boundary CFT, in particular for the free boson theory. Its lattice version, the quantum harmonic chain is also studied, and used for numerical simulations. Junctions of more than two system at a vertex are studied using the techniques of QFT on star graphs.