Experimental Implementation of a Codeword Stabilized Quantum Code

TL;DR

This paper reports the experimental implementation of a five-qubit codeword stabilized quantum error correction code using NMR, demonstrating robustness against errors and showcasing complex quantum control in spin qubits.

Contribution

It presents the first experimental realization of a nonadditive quantum code that encodes a larger space than stabilizer codes with similar length.

Findings

Quantum coherence remains robust against introduced errors.

Successful implementation of a nonadditive quantum error correction code.

Demonstrates complex quantum circuit control in spin qubits.

Abstract

A five-qubit codeword stabilized quantum code is implemented in a seven-qubit system using nuclear magnetic resonance (NMR). Our experiment implements a good nonadditive quantum code which encodes a larger Hilbert space than any stabilizer code with the same length and capable of correcting the same kind of errors. The experimentally measured quantum coherence is shown to be robust against artificially introduced errors, benchmarking the success in implementing the quantum error correction code. Given the typical decoherence time of the system, our experiment illustrates the ability of coherent control to implement complex quantum circuits for demonstrating interesting results in spin qubits for quantum computing.