PhD Comprehensive Exam | Arnaud Carignan-Dugas, A Complete Toolkit for Probing the Quantum World

A Complete Toolkit for Probing the Quantum World

Abstract

Physics is a perpetual attempt to acquire a stronger grasp on the universe, which in one hand involves the understanding of its behaviour, and in the other, the control of its dynamics. Nowadays, a lot of efforts are done in order to tame the quantum world, which still slips (to some extent) through our classical fingers. By "taming", we really mean "gaining a certain control" on the quantum scale, sufficient to harness potentially greater computational power and to increase our understanding of large quantum systems. One major obstacle to achieve such level of control is to deal with quantum errors, which structure could be exponentially more complex to describe than their classical counterparts. 
        
In this proposal, my research group and I suggest to develop a complete set of characterization tools based on randomized benchmarking techniques. Indeed, randomized benchmarking by itself is a useful tool, but should be seen as an element of a much larger set of potential probing schemes. Hence, we suggest various extensions of the original protocol in order to characterize new operations, possibly in broader physical regimes like non-Markovian dynamics. We also investigate noise's discrete dynamics in order to restrict the system's set of possible configurations after an incompletely parametrized discrete evolution. Finally, we propose to examine new characterization quantities in order to capture new noise features, like addressability and Markovianity.