Descripción del proyecto
Quantum information theory points to new ways of classifying matter. Instead of focusing on microscopic correlation functions, it hinges on global properties of quantum states such as the presence and scaling of entanglement entropy. This general strategy relates systems of vastly different scales, for example black hole physics to information propagation in microscopic quantum systems.
UniRand will realize a new, widely applicable approach to measuring global quantum state properties using ultracold atoms. At the heart of the protocol are random unitary transformations, which are applied to a quantum state before measurement. The fluctuating outcomes of measurements under random transformations encode global properties of the density matrix, including Renyi entropies and state overlaps. We are specifically interested in systems of mobile particles in optical lattices.
Random unitary protocols will give access to new physics: (1) The dynamics of information scrambling as quantified by out-of-time-order correlators and (2) the order parameter-independent characterization of quantum phase transitions through measurements of fidelity. We will probe both aspects in one-and two-dimensional bosonic Hubbard systems. Our approach will be realized on a new, high-performance quantum simulator that assembles many-body systems from individually laser-cooled atoms with a high repetition rate.
Protocols based on random unitaries in ultracold atom systems will open a new toolbox for system-level measurement and enable direct links between quantum information theory and experimental quantum science.