Quantum Physicist

Company: Infleqtion
Location: Madison
Posted on: February 11, 2026

Job Description:

Job Description Job Description Infleqtion is on a mission to commercialize atom-based quantum technologies that deliver orders-of-magnitude improvements in sensing and computing applications. As a deep-tech startup, we embrace a results-driven, fast-paced, and customer-focused approach to innovation. We are seeking self-motivated, energetic individuals with exceptional problem-solving and technical skills to help drive our Quantum Computing mission forward. We encourage applications from experimental physicists with expertise in Atomic, Molecular, and Optical (AMO) physics , particularly those with experience in the coherent control of quantum systems such as ultracold atoms, trapped ions, and diamond NV centers. Role and responsibilities Design, build, calibrate and maintain Quantum Computers based on neutral atoms. Participate and/or lead Research and Development projects for laser systems, Quantum Processing Units, quantum gate protocols, etc. for Quantum Computers. Create, test, and validate mathematical models of atomic physics behavior, and use the results to inform system design by translating high-level system requirements into specialized engineering subsystems. Self-start and successfully execute on a new R&D activity given a well-defined goal and constraints (e.g. resources, timeframe): gather requirements from stakeholders, drive definition of solution space, drive project execution. Develop, test, run, and debug software for conducting experiments and system tuning in production. Design, assemble, and test laser and optical systems. Ownership of subsystems to maintain high availability and high performance. Mentor and teach junior team members as indirect reports. Supervise interns. Requirements PhD in atomic physics, optical physics, or related field; or equivalent related professional experience (4 years); If you have substantially more experience than this and are excited to apply, please do! We will also consider hiring at the Senior Quantum Physicist level. Proficiency in using tools commonly found in an atomic physics lab, such as lasers, acousto-optic modules, RF signal generators and analyzers, and ultra-high-vacuum systems. Proficiency in writing Python code for running physics experiments. Proficiency in calculating atom-light interaction for input laser specifications. Excellent verbal and written communication skills, ability to effectively share information with technical and non-technical staff at all levels of company hierarchy. Excellent collaboration skills, ability to work in an agile efficient team environment where engagement, feedback, and participation are an expected part of successful job performance. Demonstrated problem solving skills and fast learning rate. Ability to work both autonomously—taking high-level goals as input to develop and execute an optimal plan while gathering necessary resources—and collaboratively, by soliciting and incorporating input from colleagues. It is a plus if you have: Experience in operating high power CW laser (> 1 Watt) and/or short-wavelength visible laser ( Experience with characterization and mitigation of laser frequency and intensity noise Experience with analog electronics and use of servo loops for laser and subsystem stabilization Experience with image projection through a high numerical aperture (NA) imaging system Experience in integrating heterogeneous subsystems for a complex physics experiment Familiarity with Git, Linux, and command line interface (CLI) tools Enthusiasm for staying up-to-date with latest developments in AMO physics and reviewing relevant papers for the team Note This position may require access to information protected under U.S. export control laws and regulations for quantum computing technology. Please note that any offer for employment may be conditioned on authorization to receive software or technology controlled under these U.S. export control laws and regulations without sponsorship for an export license. WORKING CONDITIONS and PHYSICAL REQUIREMENTS Work will normally be performed in an office and laboratory environment and around technical equipment including computers and lasers. We ask that candidates be able to efficiently use automated office equipment such as laptops, copiers, and printers; able to effectively engage in communications (via phone, computer, or in-person). Any required Personal Protective Equipment will be provided and must be properly used in accordance with company requirements. TRAVEL Up to 10% travel may be required. Benefits The targeted salary range for this role is $115,000 to $165,000 on an annualized basis plus eligibility to participate in our annual incentive plan. In addition to your base compensation, we offer a generous Total Rewards program which includes: 100% company paid Employee coverage for Medical, Dental, Vision, and Short/Long Term Disability insurance programs Employer funded Health Savings Account Unlimited Paid Time Off 401(k) Matching Programs Company paid Life and AD&D Insurance Flexible Healthcare Savings Account Paid FMLA Leave Paid Maternity/Paternity Leave Employer Assistance Program Student Loan Repayment Equal Opportunity Here you have freedom to embrace your whole self: who you love, your gender identity and expression, skin color, age, appearance, disability, neurodiversity, DNA, military/veteran status, citizenship, and other factors that make up who you are. Your uniqueness is valued, welcomed, and appreciated here. We are dedicated to providing a positive workplace and base all employment decisions on your qualifications, performance, merits, as well as business needs. We are proud to be an Equal Employment Opportunity Employer. Contact Information If this opportunity interests you and you fit the job description, please submit an application. If you need assistance or an accommodation due to disability, please feel free to contact us at hr@coldquanta.com.

Keywords: Infleqtion, Janesville , Quantum Physicist, Science, Research & Development , Madison, Wisconsin