We are looking for a Principal Mechanical Design Engineer – Cryo Vacuum Systems in our Broomfield, CO location to help design and de-risk next-generation trapped-ion quantum computing hardware. This role will work closely with research scientists, system architects, design engineers, and lab engineers to develop mechanical systems compatible with cryogenic operation, UHV/XHV environments, precision optical alignment, and scalable quantum computer architectures. The ideal candidate is a hands-on mechanical designer who can turn ambiguous technical risks into practical designs, prototype tests, and clear engineering recommendations.

Key Responsibilities:

• Design mechanical hardware for cryogenic and UHV trapped-ion quantum computing systems.
• Support the design of ion-trap packages, cryogenic assemblies, vacuum-compatible structures, thermal interfaces, optical alignment features, and precision mounting hardware.
• Develop designs that manage parasitic heat loads, thermal contraction, CTE mismatch, mechanical stability, vibration sensitivity, vacuum compatibility, and assembly tolerances.
• Design prototype hardware and de-risk test fixtures that lab engineers can build and operate to validate new materials, interfaces, and subsystem concepts.
• Support test planning for new materials, adhesives, thermal interfaces, coatings, cryogenic assemblies, and vacuum-compatible components.
• Work with lab engineers to evaluate outgassing, cryogenic thermal performance, mechanical stability, alignment repeatability, and failure modes.
• Perform mechanical, thermal, and tolerance analyses to guide design decisions.
• Generate CAD models, drawings, assemblies, interface definitions, and design documentation.
• Partner with vacuum, cryogenic, optical, electrical, trap fabrication, and systems teams to identify interface risks and develop practical solutions.
• Communicate design trades, assumptions, risks, test results, and recommendations to technical teams and program leadership.

You Must Have:

• Bachelor’s degree minimum
• Minimum of 7+ years (Masters and PhD inclusive) of hands-on mechanical design experience with complex hardware systems.
• Due to Contractual requirements, must be a U.S. Person. defined as, U.S. citizen permanent resident or green card holder, workers granted asylum or refugee status
• Due to national security requirements imposed by the U.S. Government, candidates for this position must not be a People's Republic of China national or Russian national unless the candidate is also a U.S. citizen. 

We Value:

• Advanced degree or higher in mechanical engineering, aerospace engineering, applied physics, materials science, or a related technical field preferred
• Experience designing mechanical components or assemblies requiring precision tolerancing, thermal management, and structural stability.
• Proficiency with 3D CAD tools and mechanical drawing release practices.
• Demonstrated ability to design hardware that can be fabricated, inspected, assembled, tested, and iterated.
• Ability to use analysis, test data, and engineering judgment to make mechanical design decisions.
• Strong written and verbal communication skills, including clear documentation of design intent, risks, assumptions, and recommendations.
• Experience with cryogenic systems, UHV vacuum systems, lasers and precision optics, AMO physics experiments, trapped-ion systems, or semiconductor packaging.
• Experience with material selection for vacuum, cryogenic, low-magnetic environments
• Experience with thermal modeling, parasitic heat-load estimation, FEA, tolerance analysis, modal analysis, or structural analysis.
• Experience designing test fixtures, prototype assemblies, or validation experiments for complex mechanical systems.
• Experience with GD&T, vendor management, machined parts, and design-for-assembly practices.
• Experience with vacuum cleanliness practices, bake-compatible design, leak checking, outgassing tests, RGA data, or cryogenic contamination control.
• Strong organizational skills and ability to manage multiple design and de-risking efforts in parallel.

The base pay range for this role is $162,000 – $218,000 annually. Actual compensation within this range may vary based on the candidate’s skills, educational background, professional experience, and unique qualifications for the role. 

Quantinuum is a leading quantum computing company delivering a full stack platform designed to make quantum computing deployable in real-world environments. With active engagements spanning pharmaceuticals, material science, financial services, government, industrial sectors, and leading academic and research institutions worldwide, we are helping organizations unlock the transformative potential of quantum computing. 

Our global team of more than 800 employees includes many of the world's leading scientists, engineers, and researchers, with more than 70% of our technology team holding advanced degrees at the Master's or PhD level. Headquartered in Broomfield, Colorado, Quantinuum operates across the United States, United Kingdom, Germany, Japan, and Singapore. 

By joining Quantinuum, you’ll help shape the future of quantum computing, pushing the limits of technology, and making the impossible possible.

What’s in it for you?

We believe our people are our greatest strength and offer a comprehensive rewards package that supports your professional growth, well-being, and long-term success.

• Competitive compensation and the opportunity to work on groundbreaking technology
• Flexible work arrangements that support work-life balance
• Employer-subsidized medical, dental, and vision insurance
• 401(k) retirement savings plan with company match and student loan repayment benefit
• Equity opportunities
• Generous paid time off, sick leave, and 12 paid holidays annually
• Paid parental leave
• Employee discount programs 

Equal Opportunity Employer

Quantinuum is proud to be an equal opportunity employer. We are committed to building an inclusive workplace where all employees and applicants are treated with respect and provided equal opportunities regardless of race, color, religion, sex, sexual orientation, gender identity or expression, national origin, age, disability, veteran status, ancestry, marital status, or any other characteristic protected by applicable law.

Know Your Rights: Workplace discrimination is illegal. For more information about Quantinuum, please visit our website. 

We are committed to making our recruitment process accessible to all. If you require any reasonable adjustments at any stage of the application or interview process, please let us know use the Lets talk contact form. 

Applications will be accepted on an ongoing basis, there is no application deadline for this position.