Quantum Characterization, Verification, and Validation Engineer

PSI Quantum; Milpitas (CA); Hybrid; USD 101,000 - 149,000; Full time

Benefits offered by this job

Health coverage

401(k) with company match

Equity grants

Financial wellness tools

Wellness benefits

Family support programs

Life and disability insurance

Paid leave

Holidays

Discretionary time off

End-of-year shutdown

Job summary

PsiQuantum is seeking a researcher to develop scalable methods for quantum characterization, verification, and validation (QCVV) of large-scale photonic quantum systems. You will design protocols to characterize quantum channels and system-level behavior where direct reconstruction is impractical, and you will connect experimental data to actionable conclusions about performance.

You will perform large-scale simulations (tensor networks, GPU-accelerated methods, Monte Carlo, stabilizer methods)

Qualifications

• PhD or equivalent experience in physics, electrical engineering, applied math, CS, or related field.
• Experience characterizing or modeling quantum channels, noisy quantum circuits, quantum processes, or error mechanisms.
• Experience developing numerical simulations for quantum systems, circuits, or noisy processes.
• Proficiency in Python for scientific computing and data analysis.

Responsibilities

• Develop scalable QCVV methods for large quantum systems and channels.
• Create statistical and numerical methods from limited, noisy data.
• Build models linking experimental data to channel behavior and error mechanisms.
• Use large-scale quantum circuit simulation to evaluate protocols and diagnose failures.
• Collaborate across theory, software, and experimental teams to compare data with models.
• Document methods, assumptions, limitations, and results clearly.

Skills

Python programming

Quantitative reasoning

Communication

Education

PhD in Physics/EE/Applied Math/CS

Tools

Stim

PyTorch

JAX

TensorFlow

CUDA/CuPy

NumPy/SciPy

ITensor

Job description

PsiQuantum's mission is to build the first useful quantum computers: machines capable of delivering the breakthroughs the field has long promised. Since our founding in 2016, our singular focus has been to build and deploy million-qubit, fault-tolerant quantum systems.

Quantum computers harness the laws of quantum mechanics to solve problems that even the most advanced supercomputers or AI systems will never reach. Their impact will span energy, pharmaceuticals, finance, agriculture, transportation, materials, and other foundational industries.

Our architectureand approachisbased on silicon photonics. Byleveragingthe advanced semiconductor manufacturing industry, including partners like GlobalFoundries, we use the same high-volume processes that already produce billions of chips for telecom and consumer electronics. Photonics offers natural advantages for scale: photonsdon'tfeel heat, are immune to electromagnetic interference, and integrate with existing cryogenic cooling and standard fiber-optic infrastructure.

That approach has since been tested at the highest level of scrutiny the U.S. government applies to emerging technology, and it has held up. In 2025,PsiQuantumclosed a$1 billionfunding round that valued the company at$7 billion. In 2026, the U.S. Department of Commerce signed a $100 million Letter of Intent under the CHIPS and Science Act, followed by a $125 million agreement with DARPA under Stage C of its Quantum Benchmarking Initiative,PsiQuantum'smost valuable U.S. government agreement to date. This year, we also broke ground on our utility-scale quantum computer in Brisbane, Australia, and continued building out our Chicago site. Victor Peng, our CEO, and co-founder Jeremy O'Brien, now ExecutiveChairman, lead a team and board that reflects how seriously the world is taking this build, joined this year by Intel's Lip-Bu Tan and Atomico's NiklasZennstrom.

PsiQuantumalso develops the algorithms and software needed to make these systems commercially valuable. Our application, software, and industry teams work directly with leading Fortune 500 companies, includingAirbus,LockheedMartin, Mercedes-Benz, Boehringer Ingelheim, and Mitsubishi Chemical, to prepare quantum solutions for real-world impact.

Quantum computing is not an extension of classical computing. Itrepresentsa fundamental shift, and a path to mastering challenges that cannot besolvedany other way. The potential is enormous, and we now havethe funding,the governmentvalidation, andthe sitesunder construction to make it real.

Job Summary:

PsiQuantum is seeking a researcher to develop methods for quantum characterization, verification, and validation (QCVV) of large-scale quantum systems. The successful candidate will work on methods for reliably characterizing quantum channels and system-level behavior in regimes where direct reconstruction is impossible. This includes developing scalable protocols, statistical analysis techniques, and simulation methods that connect experimental data to actionable conclusions about quantum performance.

Large-scale simulation is an important part of this role, particularly in the context of characterizing quantum channels, validating QCVV protocols, understanding error mechanisms, and predicting how characterization methods perform on large systems. Relevant experience may include tensor network methods, GPU-accelerated simulation, Monte Carlo methods, stabilizer simulation, and other approaches for modeling large quantum circuits and noisy quantum processes.

PsiQuantum's architecture is based on photonic quantum computing. Prior experience with photonic quantum computing is valuable but not required. Candidates should be eager to learn the relevant photonic concepts and apply their QCVV, modeling, and simulation expertise to a photonic fault-tolerant quantum computing platform.

This is a hands-on technical role in a fast-moving environment. The ideal candidate is comfortable owning research projects end to end, working across disciplines, communicating uncertainty clearly, and translating technical results into decisions that improve system characterization and performance.

Responsibilities:

• Develop scalable QCVV methods for characterizing large quantum systems, quantum channels, and system-level quantum behavior.
• Develop statistical and numerical methods for extracting meaningful performance information from limited, noisy, and indirect measurement data.
• Build models that connect observed experimental data to underlying quantum channels, error mechanisms, and system-level performance metrics.
• Use large-scale quantum circuit simulation to evaluate characterization protocols, diagnose failure modes, and understand the behavior of noisy quantum channels.
• Apply simulation methods such as tensor networks, GPU-accelerated computation, stabilizer methods, and Monte Carlo techniques where appropriate.
• Work with experimental, architecture, software, and systems teams to compare measured system behavior against theoretical and numerical models.
• Contribute to the definition of diagnostic observables and data analysis pipelines needed for reliable system characterization.
• Document methods, assumptions, limitations, and results clearly.
• Communicate progress, challenges, uncertainties, and conclusions to technical and cross-functional stakeholders.
• Take ownership of research tasks from problem definition through implementation, validation, analysis, and communication.

Experience/Qualifications:

• Ph.D. or equivalent experience in Physics, Electrical Engineering, Applied Mathematics, Computer Science, or a related field.
• Experience characterizing or modeling quantum channels, noisy quantum circuits, quantum processes, or quantum error mechanisms.
• Experience developing numerical simulations for quantum systems, quantum circuits, or noisy quantum processes.
• Programming experience for scientific computing and data analysis, preferably in Python.
• Ability to reason quantitatively about uncertainty, noise, finite statistics, model mismatch, and scalability.
• Ability to work independently on open-ended technical problems while collaborating effectively with specialists across multiple disciplines.
• Strong written and verbal communication skills, including the ability to explain technical results, assumptions, limitations, and risks clearly.

Preferred Qualifications

• Experience with one or more QCVV techniques such as randomized benchmarking, gate set tomography, cycle benchmarking, process tomography, shadow tomography, Hamiltonian learning, or related methods.
• Experience with scalable characterization methods for systems where full state or process reconstruction is not possible.
• Experience with tensor network methods for simulating quantum circuits, quantum channels, or noisy quantum processes.
• Experience running large-scale simulations on GPUs, HPC clusters, or distributed computing infrastructure.
• Experience with simulation tools and frameworks such as PyTorch, JAX, TensorFlow, CUDA, CuPy, NumPy/SciPy, ITensor, Stim, or related tools.
• Familiarity with quantum error correction, fault tolerance, logical error rates, decoder performance, Pauli errors, erasure errors, leakage, or correlated noise.
• Experience analyzing data from experimental quantum hardware platforms.
• Experience with photonic quantum computing, quantum optics, integrated photonics, measurement-based quantum computation, fusion-based quantum computation, or cluster-state models.
• Experience collaborating across theory, software, and experimental teams.

PsiQuantum provides equal employment opportunity for all applicants and employees. PsiQuantum does not unlawfully discriminate on the basis of race, color, religion, sex (including pregnancy, childbirth, or related medical conditions), gender identity, gender expression, national origin, ancestry, citizenship, age, physical or mental disability, military or veteran status, marital status, domestic partner status, sexual orientation, genetic information, or any other basis protected by applicable laws.

Note: PsiQuantum will only reach out to you using an official PsiQuantum email address and will never ask you for bank account information as part of the interview process. Please report any suspicious activity to [e-mail].

Base pay is one part of the total compensation package. Full-time roles are eligible for equity and benefits. Our compensation ranges reflect the cost of labor across multiple U.S. geographicmarkets, and we pay based on defined geographic zones. This position may be filled withinone of the followingU.S. geographic zones, each with its own salary range.

The estimated annual base salary rangefor this role is:

• Zone 1 - $126,600 — $148,700 USD
• Zone 2 - $113,900 — $133,800 USD
• Zone 3 - $101,300 — $119,000 USD
• Zone 4 - $88,600 — $104,100 USD

This position includes the following benefits: competitive health coverage for you and your dependents, 401(k) with company match, equity grants, access to financial wellness tools and planning resources, wellness benefits, family support programs, life and disability insurance, paid leave programs, company-designated paid holidays, discretionary time off (DTO), and an end-of-year company shutdown. Some of these benefits have eligibility requirements and may vary based on location, role, or employment status. Many of these benefits are subsidized or fully paid for by the company.