General scheme for the construction of a protected qubit subspace

TL;DR

This paper introduces a robust continuous dynamical decoupling scheme to create a protected qubit subspace, significantly enhancing coherence times and enabling efficient quantum operations in various atomic and solid-state systems.

Contribution

The authors propose a general multi-state qubit construction method using continuous dynamical decoupling, applicable to single levels or multiple sub-states, with demonstrated implementation in trapped ions.

Findings

Achieves a coherence time of approximately 1 second.

Enables efficient single qubit gates and cavity coupling.

Applicable to a wide range of atomic and solid-state systems.

Abstract

We present a new robust decoupling scheme suitable for levels with either half integer or integer angular momentum states. Through continuous dynamical decoupling techniques, we create a protected qubit subspace, utilizing a multi-state qubit construction. Remarkably, the multi-state system can also be comprised of multiple sub-states within a single level. Our scheme can be realized with state-of-the-art experimental setups and thus has immediate applications for quantum information science. While the scheme is general and relevant for a multitude of solid state and atomic systems, we analyze its performance for the case composed of trapped ions. Explicitly, we show how single qubit gates and an ensemble coupling to a cavity mode can be implemented efficiently. The scheme predicts a coherence time of ~1 second, as compared to typically a few milliseconds for the bare states.