Demonstrating experimentally the encoding and dynamics of an error-correctable logical qubit on a hyperfine-coupled nuclear spin qudit

TL;DR

This paper demonstrates the experimental encoding and dynamics of an error-correctable logical qubit using a hyperfine-coupled nuclear spin qudit, highlighting its potential for fault-tolerant quantum memory.

Contribution

It introduces a new implementation of a logical qubit on a nuclear spin qudit with error correction capabilities using electron-nuclear double resonance.

Findings

The encoded qubit resists magnetic field fluctuations.

The system maintains coherence under natural decoherence.

Experimental results confirm fault-tolerance potential.

Abstract

The realization of effective quantum error correction protocols remains a central challenge in the development of scalable quantum computers. Employing high-dimensional quantum systems (qudits) can offer more hardware-efficient protocols than qubit-based approaches. Using electron-nuclear double resonance, we implement a logical qubit encoded on the four states of a I=3/2 nuclear spin hyperfine-coupled to a S=1/2 electron spin qubit; the encoding protects against the dominant decoherence mechanism in such systems, fluctuations of the quantizing magnetic field. We explore the dynamics of the encoded state both under a controlled application of the fluctuation and under natural decoherence processes. Our results confirm the potential of these proposals for practical, implementable, fault tolerant quantum memories.