Anticipative measurements in hybrid quantum-classical computation

TL;DR

This paper introduces anticipative quantum measurements that leverage classical information to improve success rates in hybrid quantum-classical tasks, enabling parallel execution and demonstrating benefits on real noisy quantum devices.

Contribution

It presents a novel anticipative measurement approach that enhances hybrid quantum-classical computation by utilizing classical information without feedback, demonstrated on IBMQ hardware.

Findings

Improved success rate with anticipative measurements on IBMQ.

Parallel execution of quantum and classical computations is feasible.

Method is effective in noisy intermediate-scale quantum devices.

Abstract

Before the availability of large scale fault-tolerant quantum devices, one has to find ways to make the most of current noisy intermediate-scale quantum devices. One possibility is to seek smaller repetitive hybrid quantum-classical tasks with higher fidelity, rather than directly pursuing large complex tasks. We present an approach in this direction where the quantum computation is supplemented by a classical result. While the presence of the supplementary classical information helps alone, taking advantage of its anticipation also leads to a new type of quantum measurements, which we call anticipative. Anticipative quantum measurements lead to improved success rate over cases where we would use quantum measurements optimized without assuming the later arriving supplementing information. Importantly, in an anticipative quantum measurement the combination of the results from classical and quantum computations happens only in the end, without the need for feedback from the one to the other computation, a feature which hence allows for running both computations in parallel. We demonstrate the method with an experiment using an IBMQ device and show that it leads to an improved success rate even in a real noisy setting.