Senior Cryogenic Engineer

About IonQ: 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. Headquartered in College Park, Maryland, IonQ has operations in California, Colorado, Massachusetts, Tennessee, Washington, Italy, South Korea, Sweden, Switzerland, Canada, and the United Kingdom. Our quantum computing services are available through all major cloud providers, while we also meet the needs of networking and sensing customers across land, sea, air, and space. IonQ is making quantum platforms more accessible and impactful than ever before. What to Expect We are seeking a Senior Cryogenic Engineer to support and develop advanced cryogenic platforms for our SNSPD (Superconducting Nanowire Single-Photon Detector) product line, with a strong emphasis on next-generation rack-mountable systems. You will join a cross-functional team dedicated to advancing world-class quantum technologies that address some of the most complex challenges in computing, networking, and sensing. In this role, you will play a central part in the development lifecycle, overseeing cryogenic subsystems and ensuring robust, reliable 2K cryo-systems that can be deployed across internal and customer environments, while remaining maintainable and adaptable as the technology evolves. What You'll be Doing Working at the intersection of engineering and innovation, you will lead system-level specification, integration, and testing of cryogenic platforms tailored to SNSPD requirements. You will collaborate closely with internal teams, subcontractors, and external partners to design, configure, and improve deployable systems, while also providing operational support for existing platforms. What you'll Bring This position suits a highly experienced engineer with a strong background in cryogenic systems, hands-on expertise with cryostats and related technologies, and the ability to drive integration efforts across multidisciplinary teams and external vendors. You'll be a great fit with: - Master’s degree (PhD preferred) in applied physics, system engineering, mechanical engineering, or a related field, with 5-7+ years of experience in the cryogenic industry - Proven experience designing, evaluating, and maintaining complex cryogenic systems, including dilution, sorption, and 1 K cryostats - Strong knowledge of cryogenic wiring, sensors, electronics, and CAD-based design and manufacturing processes - Experience collaborating with cryogenic vendors, subcontractors, and external design partners on system integration - Desirable expertise in fibre or free-space optics, superconducting nanowire single-photon detectors, and leading integration projects Compensation will vary based on individual factors such as education, qualifications, and experience of the final candidate(s), specific office location, and calibration against relevant market data and internal team equity. Posted base salary figures are subject to change as new market data becomes available. Our benefits include comprehensive medical, dental, and vision plans, matching 401(k), unlimited PTO and paid holidays, parental/adoption leave, legal insurance, and a home technology stipend. Details of participation in these benefit plans will be provided when a candidate receives an offer of employment. At IonQ, we believe in fair treatment, access, opportunity, and advancement for all while striving to identify and eliminate barriers. We empower employees to thrive by fostering a culture of autonomy, productivity, and respect. We are dedicated to creating an environment where individuals can feel welcomed, respected, supported, and valued. We are committed to equity and justice. We welcome different voices and viewpoints and do not discriminate on the basis of race, religion, ancestry, physical and/or mental disability, medical condition, genetic information, marital status, sex, gender, gender identity, gender expression, transgender status, age, sexual orientation, military or veteran status, or any other basis protected by law. We are proud to be an Equal Employment Opportunity employer. US Technical Jobs. The position you are applying for will require access to technology that is subject to U.S. export control and government contract restrictions. Employment with IonQ is contingent on either verifying “U.S. Person” (e.g., U.S. citizen, U.S. national, U.S. permanent resident, or lawfully admitted into the U.S. as a refugee or granted asylum) status for export controls and government contracts work, obtaining any necessary license, and/or confirming the availability of a license exception under U.S. export controls. Please note that in the absence of confirming you are a U.S. Person for export control and government contracts work purposes, IonQ may choose not to apply for a license or decline to use a license exception (if available) for you to access export-controlled technology that may require authorization, and similarly, you may not qualify for government contracts work that requires U.S. Persons, and IonQ may decline to proceed with your application on those bases alone. Accordingly, we will have some additional questions regarding your immigration status that will be used for export control and compliance purposes, and the answers will be reviewed by compliance personnel to ensure compliance with federal law. US Non-Technical Jobs. Due to applicable export control laws and regulations, candidates must be a U.S. citizen or national, U.S. permanent resident (i.e., current Green Card holder), or lawfully admitted into the U.S. as a refugee or granted asylum. Accordingly, we will have some additional questions regarding your immigration status that will be used for export control and compliance purposes, and the answers will be reviewed by compliance personnel to ensure compliance with federal law. If you are interested in being a part of our team and mission, we encourage you to apply!