Bayesian Quantum Multiphase Estimation Algorithm

Understand

Quantum phase estimation (QPE) is the key subroutine of several quantum computing algorithms as well as a central ingredient in quantum computational chemistry and quantum simulation.

• While QPE strategies have focused on the estimation of a single phase, applications to the simultaneous estimation of several phases may bring substantial advantages; for instance, in the presence of spatial or temporal constraints.
• In this work, we study a Bayesian algorithm for the parallel (simultaneous) estimation of multiple arbitrary phases.
• The protocol gives access to correlations in the Bayesian multi-phase distribution resulting in covariance matrix elements scaling inversely proportional to the square of the total number of quantum resources.