Project description
A novel quantum simulator helps scientists think globally while acting locally
It is not always easy to observe experimental realisations of theoretical predictions, yet this cycle is critical to enhancing our understanding of all types of phenomena. In the realm of quantum physics, ultracold atom systems at temperatures near absolute zero have enabled many breakthroughs and opportunities to test predictions. The EU-funded UniRand project is developing a high-performance quantum simulator that creates many-body systems from individual cold atoms. It will help scientists experimentally address the ways in which small perturbations to a single quantum state can cause outcomes or signals that encode the global properties of the system's quantum states. Success could yield a new toolbox for system-level quantum measurements and provide a link between quantum information theory and experimental quantum science.
Objective
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.
Fields of science
Programme(s)
Topic(s)
Funding Scheme
ERC-STG - Starting GrantHost institution
80539 Munchen
Germany