Bidirectional microwave-optical conversion with an integrated soft-ferroelectric barium titanate transducer

Abstract

Efficient, low-noise, and high-bandwidth transduction between optical and microwave photons is key to long-range quantum communication between distant superconducting quantum processors. Recent demonstrations of microwave-optical transduction using the broadband direct electro-optic (Pockels) effect in optical thin films made of AlN or LiNbO${}_3$ have shown promise. To improve efficiency and added noise, materials with larger Pockels coefficients, such as the soft ferroelectrics BaTiO${}_3$ or SrTiO${}_3$, are required. However, these materials require adapted designs and fabrication approaches due to their nonlinear and, in some cases, hysteretic electro-optic response. Here, we engineer an on-chip, triply resonant transducer comprising low-loss BaTiO${}_3$-on-SiO${}_2$ waveguides monolithically integrated with a superconducting microwave resonator made of Nb. We demonstrate bidirectional microwave-optical transduction and reach total off-chip efficiencies of $1\times 10^{-6}$ using pulsed pumping. Our novel device concept permits in-situ poling of the ferroelectric material without introducing excess microwave loss, using a fully subtractive fabrication process with superconducting air bridges. In addition, we investigate optically induced heating, revealing fast thermalization and quasiparticle resilience of the microwave resonator. Our transducer concept and fabrication process are applicable to other materials with a large bias-induced Pockels effect and pave the way for efficient, low-power quantum interconnects.

31 pages, 30 figures

References in corpus (33)

• The Quantum Internet
• Cavity Optomechanics
• Ground-to-satellite quantum teleportation
• Remote quantum entanglement between two micromechanical oscillators
• Quantum transduction of optical photons from a superconducting qubit
• The Future of Quantum Computing with Superconducting Qubits
• Perspectives on quantum transduction
• Entanglement of Nanophotonic Quantum Memory Nodes in a Telecom Network
• Telecom-heralded entanglement between remote multimode solid-state quantum memories
• Entangling single atoms over 33 km telecom fibre
• Cavity quantum electro-optics
• A multinode quantum network over a metropolitan area
• Two-Dimensional Optomechanical Crystal Cavity with High Quantum Cooperativity
• Bidirectional electro-optic conversion reaching 1% efficiency with thin-film lithium niobate
• Cavity quantum electro-optics. II. Input-output relations between traveling optical and microwave fields
• Contribution of dielectrics to frequency and noise of NbTiN superconducting resonators
• Metropolitan-scale heralded entanglement of solid-state qubits
• Optically-Heralded Entanglement of Superconducting Systems in Quantum Networks
• Entangling microwaves with optical light
• A perspective on hybrid quantum opto- and electromechanical systems
• Cavity quantum electro-optics: Microwave-telecom conversion in the quantum ground state
• Quantum-enabled interface between microwave and telecom light
• Disentangling Losses in Tantalum Superconducting Circuits
• An integrated microwave-to-optics interface for scalable quantum computing
• Microwave-to-optical conversion with a gallium phosphide photonic crystal cavity
• Surpassing the resistance quantum with a geometric superinductor
• Ground-state Pulsed Cavity Electro-optics for Microwave-to-optical Conversion
• Figures of merit for quantum transducers
• Piezoelectric actuation for integrated photonics
• All-optical single-shot readout of a superconducting qubit
• Vacuum Beam Guide for Large-Scale Quantum Networks
• Quantum paraelectricity probed by superconducting resonators
• Absorption loss and Kerr nonlinearity in barium titanate waveguides

Cited by in corpus (1)

• Review of Superconducting Qubit Devices and Their Large-Scale Integration