Entangling gates on degenerate spin qubits dressed by a global field

TL;DR

This paper demonstrates the implementation of entangling two-qubit gates on degenerate spin qubits dressed by a global field, showing progress towards scalable, noise-resilient quantum computing with simplified control schemes.

Contribution

It presents the first demonstration of simultaneous global control and addressability of degenerate dressed spin qubits, including driven two-qubit gates like SWAP oscillations.

Findings

Successful on-resonance driving of degenerate qubits with global fields

Implementation of driven two-qubit SWAP gates

Dressing enhances noise robustness of entangling operations

Abstract

Coherently dressed spins have shown promising results as building blocks for future quantum computers owing to their resilience to environmental noise and their compatibility with global control fields. This mode of operation allows for more amenable qubit architecture requirements and simplifies signal routing on the chip. However, multi-qubit operations, such as qubit addressability and two-qubit gates, are yet to be demonstrated to establish global control in combination with dressed qubits as a viable path to universal quantum computing. Here we demonstrate simultaneous on-resonance driving of degenerate qubits using a global field while retaining addressability for qubits with equal Larmor frequencies. Furthermore, we implement SWAP oscillations during on-resonance driving, constituting the demonstration of driven two-qubit gates. Significantly, our findings highlight the fragility of entangling gates between superposition states and how dressing can increase the noise robustness. These results represent a crucial milestone towards global control operation with dressed qubits. It also opens a door to interesting spin physics on degenerate spins.