Applied Physicist - Quantum RF Sensing Lab Engineer

Infleqtion; Louisville (KY); On-site; USD 145,000 - 170,000; Full time

Benefits offered by this job

Health insurance

401(k) match

Unlimited PTO

Equity program

Employer-funded HSA

Job summary

Infleqtion seeks an Applied Physicist to build, operate, and improve experimental platforms for Rydberg-atom RF sensing. You will own defined experiments, translate atomic/optical/RF behavior into sensor improvements, and carry validated improvements into integrated QRF systems.

This is hands‑on lab work with modeling supporting design and interpretation. Reporting to the Director of R&D, Quantum RF, you will work with RF, optics, mechanical, electronics, and software teams to deliver stable,

Qualifications

• Hands-on experimental experience with lasers, optics, RF hardware.
• Ability to design and run controlled experiments.
• Experience with data analysis and uncertainty quantification.
• Knowledge of RF measurements and test equipment.
• Strong collaboration across physics, engineering, and product teams.

Responsibilities

• Own defined experimental campaigns addressing QRF sensitivity, noise, stability, bandwidth, dynamic range, and repeatability.
• Build, align, commission, operate, maintain, and troubleshoot persistent testbeds that integrate lasers and optics, atomic-sensing hardware, RF and electronic instrumentation, controls, and data acquisition.
• Design and execute controlled experiments that isolate performance limitations and convert results into specific hardware, operating-point, calibration, or control-system improvements.
• Integrate validated experimental improvements into sensor heads, subsystems, and complete QRF systems; verify performance against quantitative requirements and documented test methods.
• Characterize vapor cells and RF resonators, including thermal, optical, geometric, material, field-delivery, and repeatability effects that influence sensor performance.
• Establish and maintain laser-frequency locks, optical-power stability, photodetection, and associated noise-characterization methods.
• Calibrate and characterize RF delivery through electrodes, resonators, antennas, TEM or GTEM cells, and related test configurations using appropriate RF and microwave instrumentation.
• Develop automated instrument-control, parameter-sweep, optimization, calibration, and data-analysis workflows using Python or comparable scientific tools.
• Analyze experimental data with appropriate uncertainty, noise, and repeatability treatment; use atomic, optical, or electromagnetic models to guide experiments, interpret results, and investigate discrepancies among predicted, benchtop, subsystem, and integrated-system performance.
• Translate findings into design recommendations, configuration records, test procedures, technical reports, and verification evidence that engineers and technicians can reproduce.
• Work with RF, optical‑mechanical, electrical, embedded‑software, systems, and technician personnel to make experimental configurations stable, maintainable, and transferable.
• Provide occasional support for laboratory or field demonstrations and customer‑program testing as assigned, following applicable safety, export‑control, configuration‑control, and documentation requirements.
• Bachelor’s degree in physics, applied physics, optical engineering, electrical engineering, or a closely related field plus at least four years of relevant hands‑on experimental experience; a master’s degree plus at least two years; or a PhD with directly relevant experimental research.
• Demonstrated hands‑on experience personally building, aligning, operating, and troubleshooting complex experimental apparatus that integrates two or more of the following: lasers or optics, electronics, RF or microwave hardware, thermal or mechanical hardware, and software or controls.
• Practical experience with laser and optical alignment, photodetection, electronic instrumentation, and diagnosis of noise, stability, or performance limitations.
• Working knowledge of RF measurements and experience using equipment such as signal generators, spectrum analyzers, oscilloscopes, or vector network analyzers.
• Ability to design controlled experiments, analyze noisy data, assess measurement uncertainty and repeatability, and draw defensible conclusions from incomplete or conflicting results.
• Experience automating experiments and analyzing data using Python or a comparable scientific programming environment.
• Ability to independently plan and execute defined laboratory work, document results clearly, and collaborate across physics, engineering, and product disciplines while seeking senior direction for broader architecture and scientific strategy.
• Comfortable working in a fast‑moving environment where designs, schedules, and supplier constraints evolve quickly.

Skills

Experimental physics

Lab automation

Python programming

RF measurements

Optical alignment

Education

Bachelor’s degree in physics or related field

Master’s degree or PhD preferred

Tools

Python

Oscilloscope

Vector Network Analyzer

Spectrum Analyzer

Laser systems

Job description

Infleqtion seeks an Applied Physicist to build, operate, and improve experimental platforms for Rydberg-atom RF sensing. You will own defined experiments, translate atomic/optical/RF behavior into sensor improvements, and carry validated improvements into integrated QRF systems.

This is hands‑on lab work with modeling supporting design and interpretation. Reporting to the Director of R&D, Quantum RF, you will work with RF, optics, mechanical, electronics, and software teams to deliver stable,