QRF Physicist

Infleqtion is a global quantum technology company solving the world’s most challenging problems. The company harnesses quantum mechanics to build and integrate quantum computers, sensors, and networks. From fundamental physics to leading edge commercial products, Infleqtion enables “quantum everywhere” through our ecosystem of devices and platforms. POSITION SUMMARY Infleqtion’s Quantum RF (QRF) group is seeking a Physicist to support the development and experimental validation of Rydberg-atom-based RF sensing systems. The successful candidate will work in a hands-on lab environment building and testing integrated optical, electronic, and RF systems that push the limits of quantum sensing performance. This role is ideal for an early-career physicist with experience in experimental AMO physics and a working understanding of RF systems who thrives in a highly interdisciplinary setting. JOB RESPONSIBILITIES The duties and responsibilities below represent core expectations for this role. Depending on experience and project needs, this position may perform a combination of these tasks or take lead responsibility in specific areas. Support experimental work involving Rydberg atom–based RF sensors and subsystems. Assist in the design, assembly, and alignment of laser, optical, and RF systems. Operate and troubleshoot laboratory instrumentation, including photodiodes, spectrum analyzers, signal generators, and oscilloscopes. Contribute to integration of optical, electronic, and RF components into compact, ruggedized systems. Perform measurement campaigns to characterize sensitivity, noise, and dynamic range of prototype devices. Support modeling and data analysis for atomic and electromagnetic phenomena using Python, Ansys, or similar tools. Work closely with physicists and RF engineers to iterate design improvements and document experimental findings. Participate in internal reviews and external reporting (technical memos, figures, and presentations). Maintain accurate lab documentation and ensure proper handling of technical data subject to ITAR/EAR regulations. EDUCATION AND EXPERIENCE BS or MS in Physics, Applied Physics, or Electrical Engineering (focus in AMO, optics, or RF preferred). 0–4 years of relevant hands-on lab experience (academic or industry). Experience aligning and operating diode lasers and optical systems. Familiarity with optical modulation hardware (AOMs, EOMs, photodiodes). Familiarity with ultra-high vacuum and/or vapor cells used in alkali atom-based systems. Basic understanding of RF concepts such as frequency mixing, modulation, and signal detection. Experience with data acquisition and control software, e.g., LabVIEW, Python, or MATLAB. DESIRED SKILLS Strong documentation, communication, and teamwork skills Experience with single or multi-photon atomic spectroscopy techniques, e.g., electromagnetically induced transparency (EIT). Familiarity with RF measurement tools (VNA, spectrum analyzer, signal generator). Experience with opto-mechanical CAD tools or experimental modeling software. Curiosity and drive to work across optics, electronics, and RF domains TRAVEL Up to 10% local travel may be required. WORKING CONDITIONS and PHYSICAL REQUIREMENTS Work will be performed in an office and laboratory environment around lasers, RF sources, and technical equipment. Must be able to lift up to 40 lbs and comply with all safety procedures and PPE requirements EXPORT CONTROL This position may require access to information protected under U.S. export control laws and regulations, including the EAR and ITAR. Offers may be conditioned on authorization to receive controlled technology without sponsorship for an export license. Benefits Salary range: 90,000 to 120,000 USD/Year 100% company-paid medical, dental, vision, short/long-term disability Employer-funded Health Savings Account Unlimited PTO 401(k) match Company-paid Life and AD&D Insurance Flexible Savings Account Paid FMLA, Maternity/Paternity Leave Employee Assistance Program Student Loan Repayment Equity Program