Graduate Student Seminar | Maria Papageorgiou, Seminar 3: Detector models in Quantum Field Theory: frictions with relativistic causality

Zoom: please contact amgrad@uwaterloo for the meeting link

Speaker

Maria Papageorgiou | University of Waterloo

Title

Seminar 3: Detector models in Quantum Field Theory: frictions with relativistic causality 

Please note: this is apart of a seminar series

Abstract

Unruh DeWitt-type detectors are typically defined as controllable non-relativistic systems that are locally coupled to a quantum field. Due to the non-relativistic character of the detector, it is not guaranteed that the model is compatible with relativistic causality. In this seminar I will analyze potential causality violations in Unruh DeWitt-type detector models, that are commonly used in the field of Relativistic Quantum Information. First, I will explain the relation between faster-than-light signaling and the causal factorization of the dynamics for multiple detector-field interactions. Then, I will demonstrate how spatially extended non-relativistic detector models predict superluminal propagation of the field's initial conditions. Based on this, I will discuss the validity of measurements in Quantum Field Theory when performed with non-relativistic detectors (e.g. qubits).