Analog Mixed-Signal Design and Modelling Engineer

IonQ, Inc . [NYSE: IONQ] is the world's leading quantum platform and merchant supplier - delivering integrated quantum solutions across computing, networking, sensing, and security. IonQ's newest generation of quantum computers, the IonQ Tempo, is the latest in a line of cutting-edge systems that have been helping customers and partners including Amazon Web Services, and AstraZeneca achieve 20x performance results and accelerate innovation in drug discovery, materials science, financial modeling, logistics, cybersecurity, and defense.

In 2025, the company achieved 99.99% two-qubit gate fidelity, setting a world record in quantum computing performance .

This role is based at our Oxford, England (UK) office, with the option to work a few days a week remotely.

Up to 5%

1765

We are looking for a Staff Analog Mixed-Signal Design and Modelling Engineer to join our Cryo-CMOS IC team at IonQ Oxford. In this role, you will develop behavioural models and mixed-signal verification environments for ASICs used in our trapped-ion quantum processors.

In this position, you will build and maintain the model of the chip that the whole team simulates against, a mixed-abstraction model combining transistor-level circuits with Verilog-A/Verilog-AMS and System Verilog real-number behavioural blocks. These models will be derived form first-principles mathematics and correlated against schematic and measured silicon. You will decide which blocks are represented at which level of abstraction, keep the models faithful to the schematics and measured silicon.

The full-chip model will then be used to verify the ASICs that control the quantum processor from room temperature down to a few kelvin.

You will develop verification plans, run simulations and regressions, and validate models against circuit simulations and available silicon measurements. As a Staff Engineer, you will lead modelling and verification reviews, help define sign-off criteria and mentor other engineers. Your work will support tape-out and silicon bring-up, helping deliver reliable control electronics for IonQ's quantum computing systems.

Key responsibilities include:

• Own the full-chip modelling strategy: model architecture, abstraction levels, accuracy targets and sign-off criteria used across the IC development flow
• Owning analog and mixed-signal blocks (references, DACs, switches, regulators, clock distribution) from specification through schematic design
• Own top-level integration: define block interfaces and specifications, assemble the top level, and run the full-chip mixed-signal simulations that verify the ASIC Develop Verilog-A and Verilog-AMS models of analog blocks and assemble them into a simulatable full chip
• Build real-number models so the full chip runs in digital verification and regression at practical speed
• Derive models from mathematics: turn a transfer function, a Z-parameter network description or a MATLAB analysis into robust Verilog-A with well-behaved tolerances
• Define and run model-versus-schematic correlation, keeping models in sync with design releases, and feed measured silicon behaviour, back into the models and the block designs
• Develop verification plans from specifications, covering operating modes, analog-digital interfaces, power-up and reset sequences, and relevant process, voltage and temperature conditions.
• Stand up mixed-signal co-simulation and regression (Cadence AMS Designer, Xcelium with Spectre) Lead block-level design reviews and mentor engineers on circuit design and modelling craft
• Lead modelling and verification reviews, define AMS sign-off criteria with the IC Lead, and present coverage, correlation results and risks for tape-out decisions
• Mentor engineers in modelling and verification

To be successful, you will need deep analog and mixed-signal design and modelling experience, typically 10+ years. You will have designed blocks proven in silicon and models and used in production tape-out flows. You will bring expert transistor-level design of precision analog blocks (references, DACs, regulators, switches, clock distribution) taken through PVT and Monte Carlo, layout and silicon validation, together with expert Verilog-A and Verilog-AMS and strong real-number modelling.

You'd be a great fit with:

• Multiple tape-outs with responsibility for block design and top-level integration, including silicon bring-up and bench characterisation
• Strong mathematical foundations: linear systems,…