Error Mitigation and Quantum-Assisted Simulation in the Error Corrected Regime

A standard approach to quantum computing is based on the idea of promoting a classically simulable and fault-tolerant set of operations to a universal set by the addition of magic quantum states. In this context, we develop a general framework to discuss the value of the available, nonideal magic resources, relative to those ideally required. We single out a quantity, the quantum-assisted robustness of magic (QROM), which measures the overhead of simulating the ideal resource with the nonideal ones through quasiprobability-based methods. This extends error mitigation techniques, originally developed for noisy intermediate-scale quantum devices, to the case where qubits are logically encoded. The QROM shows how the addition of noisy magic resources allows one to boost classical quasiprobability simulations of a quantum circuit and enables the construction of explicit protocols, interpolating between classical simulation and an ideal quantum computer.

Automated summary

The article introduces a standard approach to quantum computing by promoting a set of classical operations to a universal set with the addition of magic quantum states, and introduces a new concept of quantum-assisted robustness of magic (QROM) to measure the value of magic resources. The QROM technique shows how adding noisy magic resources can enhance classical quasiprobability simulations of a quantum circuit.