IQI Weekly Seminar

Abstract: Symmetry principles are powerful and unifying concepts in modern physics, however they are usually associated with conservation laws and reversible dynamics. Here I will discuss an information-theoretic framework that extends traditional techniques from Lagrangian dynamics to general quantum operations. At its core is a polar decomposition for quantum processes that specifies the minimal resources needed to realise the process subject to an underlying symmetry principle. The techniques lead to a novel information-theoretic perspective on gauge theories, as well as connections with recent QI work on quantum thermodynamics. In particular I will present a complete set of entropic conditions for quantum thermodynamics based on simple physical principles of stability and microscopic energy conservation. In addition to the symmetry analysis, the entropic conditions exploit a recently developed generalization of majorization theory.