Algorithmic cooling for resolving state preparation and measurement errors in quantum computing

TL;DR

This paper introduces measurement-based algorithmic cooling (MBAC), a method to distinguish and reduce state preparation errors from measurement errors in quantum computing, enhancing processor benchmarking and performance.

Contribution

The paper proposes MBAC, a novel protocol that separately characterizes and reduces SPAM errors using imperfect measurements, with practical overhead bounds.

Findings

MBAC significantly reduces state preparation errors.

The overhead of MBAC can be bounded by measurable quantities.

MBAC improves quantum processor benchmarking and performance.

Abstract

State preparation and measurement errors are commonly regarded as indistinguishable. The problem of distinguishing state preparation (SPAM) errors from measurement errors is important to the field of characterizing quantum processors. In this work, we propose a method to separately characterize SPAM errors using a novel type of algorithmic cooling protocol called measurement-based algorithmic cooling (MBAC). MBAC assumes the ability to perform (potentially imperfect) projective measurements on individual qubits, which is available on many modern quantum processors. We demonstrate that MBAC can significantly reduce state preparation error under realistic assumptions, with a small overhead that can be upper bounded by measurable quantities. Thus, MBAC can be a valuable tool not only for benchmarking near-term quantum processors, but also for improving the performance of quantum processors in an algorithmic manner.