Purification-based quantum error mitigation of pair-correlated electron simulations

Understand

An important measure of the development of quantum computing platforms has been the simulation of increasingly complex physical systems.

• Prior to fault-tolerant quantum computing, robust error mitigation strategies are necessary to continue this growth.
• Here, we study physical simulation within the seniority-zero electron pairing subspace, which affords both a computational stepping stone to a fully correlated model, and an opportunity to validate recently introduced ``purification-based'' error-mitigation strategies.
• We compare the performance of error mitigation based on doubling quantum resources in time (echo verification) or in space (virtual distillation), on up to $20$ qubits of a superconducting qubit quantum processor.