Stability Experiments: The Overlooked Dual of Memory Experiments

TL;DR

This paper introduces 'stability experiments' as a new benchmark for assessing how effectively quantum error correction systems can move logical observables through space, complementing existing memory experiments.

Contribution

It proposes a novel stability experiment framework to evaluate the spatial movement of logical observables in topological quantum computation.

Findings

Stability experiments provide a new benchmark for quantum systems.

They test the ability to determine products of stabilizers over large regions.

The approach complements existing memory experiments.

Abstract

Topological quantum computations are built on a foundation of two basic tasks: preserving logical observables through time and moving logical observables through space. Memory experiments, which check how well logical observables are preserved through time, are a well established benchmark. Strangely, there is no corresponding well established benchmark for moving logical observables through space. This paper tries to fill that gap with "stability experiments", which check how well a quantum error correction system can determine the product of a large region of stabilizers. Stability experiments achieve this by testing on a region that is locally a normal code but globally has a known product of stabilizers.