Certified quantum gates

TL;DR

This paper proposes a method for quantum error detection in small, near-term quantum processors that uses internal states to identify certain gate errors without extra qubits, enhancing the reliability of quantum computations.

Contribution

It introduces a novel error detection strategy leveraging internal states, applicable to universal gate sets in trapped ion platforms, without requiring additional physical qubits.

Findings

Error detection can certify individual gates against specific errors.

The method allows post-computation error flagging through irreversible detection.

Applicable to small quantum processors lacking full error correction.

Abstract

High quality, fully-programmable quantum processors are available with small numbers (<1000) of qubits, and the scientific potential of these near term machines is not well understood. If the small number of physical qubits precludes practical quantum error correction, how can these error-susceptible processors be used to perform useful tasks? We present a strategy for developing quantum error detection for certain gate imperfections that utilizes additional internal states and does not require additional physical qubits. Examples for adding error detection are provided for a universal gate set in the trapped ion platform. Error detection can be used to certify individual gate operations against certain errors, and the irreversible nature of the detection allows a result of a complex computation to be checked at the end for error flags.