Limitations in quantum computing from resource constraints

TL;DR

This paper investigates how resource limitations in physical quantum systems affect error correction capabilities, establishing a maximum achievable accuracy and providing tools for resource optimization in quantum computing.

Contribution

It introduces a method to optimize error correction considering resource constraints, defining the maximum attainable accuracy and minimum resources needed for quantum algorithms.

Findings

Maximum computational accuracy under resource constraints

Resource optimization framework for quantum error correction

Energetic estimates for large-scale quantum computers

Abstract

Fault-tolerant schemes can use error correction to make a quantum computation arbitrarily ac- curate, provided that errors per physical component are smaller than a certain threshold and in- dependent of the computer size. However in current experiments, physical resource limitations like energy, volume or available bandwidth induce error rates that typically grow as the computer grows. Taking into account these constraints, we show that the amount of error correction can be opti- mized, leading to a maximum attainable computational accuracy. We find this maximum for generic situations where noise is scale-dependent. By inverting the logic, we provide experimenters with a tool to finding the minimum resources required to run an algorithm with a given computational accuracy. When combined with a full-stack quantum computing model, this provides the basis for energetic estimates of future large-scale quantum computers.