Filter Functions for Quantum Processes under Correlated Noise

Understand

Many qubit implementations are afflicted by correlated noise not captured by standard theoretical tools that are based on Markov approximations.

• While independent gate operations are a key concept for quantum computing, it is actually not possible to fully describe noisy gates locally in time if noise is correlated on times longer than their duration.
• To address this issue, we develop a method based on the filter function formalism to perturbatively compute quantum processes in the presence of correlated classical noise.
• We derive a composition rule for the filter function of a sequence of gates in terms of those of the individual gates.