Quantum Algorithms Researcher (Senior/Staff)

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 architecture and approach is based on silicon photonics. By leveraging the 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: photons don't feel 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, PsiQuantum closed a $1 billion funding 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's most 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 Executive Chairman, 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 Niklas Zennström. PsiQuantum also 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, including Airbus, Lockheed Martin, Mercedes-Benz, Boehringer Ingelheim, and Mitsubishi Chemical, to prepare quantum solutions for real-world impact. Quantum computing is not an extension of classical computing. It represents a fundamental shift, and a path to mastering challenges that cannot be solved any other way. The potential is enormous, and we now have the funding, the government validation, and the sites under construction to make it real. Job Summary: PsiQuantum is seeking a Senior Quantum Algorithms Researcher to join the Quantum Algorithms team within our Applications Development department. This role offers the opportunity to help define how large-scale, fault-tolerant quantum computers will be applied to consequential real-world problems in chemistry, pharmaceuticals, and materials science. At PsiQuantum, we believe in the transformative potential of quantum computing to solve problems beyond the reach of classical computation. For the first quantum computers to be useful, we believe they must be fault tolerant. This conviction shapes our approach to applications research. Rather than developing algorithms for near-term or intermediate-scale devices, we focus on quantum algorithms designed for the fault-tolerant regime, where, specifically, the cost of a quantum algorithm is determined by its runtime on a fusion-based, fault-tolerant quantum computer built on silicon photonic hardware. In the Quantum Algorithms team, we adapt and develop quantum algorithms, scope and identify promising use cases, and analyze resource requirements. In your role, you will translate computational tasks into abstract specifications for quantum algorithms, analyze their asymptotic performance, and help define meaningful problem instances that lie beyond the practical reach of classical computation. You will also work closely with PsiQuantum’s Compilation team to develop explicit instantiations of these algorithms and understand their resource requirements on our architecture. We are particularly interested in candidates with deep expertise in quantum simulation. Relevant areas may include simulated time-evolution algorithms, quantum algorithms for estimating the energies of molecular or periodic systems, and methods for preparing candidate ground states of model Hamiltonians. More broadly, the successful candidate will bring substantial expertise in a specific subfield of quantum algorithms, together with the ability to connect fundamental algorithmic research to computationally and industrially relevant problems. In this position, you will be expected not only to conduct outstanding individual research but also to formulate and lead broader research programs that encompass the work of other researchers and collaborators. You will contribute to cross-team initiatives across PsiQuantum’s applications, architecture, and compilation efforts, helping to connect algorithm design with the practical requirements of fault-tolerant quantum computation. The role may also include external engagements. You will have the opportunity to lead projects with industrial and research partners, working with domain experts to identify important computational challenges, extract well-defined problem formulations, and map those problems to appropriate quantum algorithms. This requires the ability to communicate across disciplinary boundaries and to move fluently between real-world applications, mathematical abstractions, algorithmic complexity, and implementation-level resource analysis. The ideal candidate combines deep technical expertise with scientific leadership, intellectual independence, and a strong collaborative mindset. They will be comfortable shaping open-ended research directions, evaluating the practical significance of algorithmic advances, and guiding projects from the initial identification of an application through to a concrete fault-tolerant quantum algorithm and resource estimate. Responsibilities: • Propose initiatives into research and development of quantum algorithms tailored for fault-tolerant quantum computers; act as primary contributor to research programs beyond the current state of the art in quantum algorithms design. • Work closely with external partners to instantiate, validate and optimize quantum algorithms for use cases across a variety of domains, such as life sciences, industry and sustainability. • Establish families of benchmarks and problem instances to validate post-classicality of quantum algorithms. • Guide both the simulation and analysis of resource requirements for fault tolerant implementation of quantum algorithms in photonic quantum computing. Experience/Qualifications: • 8+ years of research experience (academia or industry) in the field of quantum computing, with focus on algorithms and applications.   • A degree in Physics, Math or Computer Science or equivalent is required. PhD in Physics, Math or Computer Science, with a focus on quantum information theory or quantum computation will be preferred.  • Experience with quantum algorithms and compiling in the regime of fault tolerant gates preferred . • Experience working with partners in academia or industry to analyze real-world quantum applications of interest preferred. • Proven team player with an ability to work effectively across departments, sites and time zones. • Ability to work independently and contribute to fast-moving start-up environment.  • Experience programming in Python, C++ or similar languages. 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 recruiting@psiquantum.com. We are not accepting unsolicited resumes from employment agencies. The ranges below reflect the target ranges for a new hire base salary. Actual compensation may vary outside of these ranges and is dependent on various factors including but not limited to a candidate's qualifications including relevant education and training, competencies, experience, geographic location, and business needs. Base pay is only one part of the total compensation package. Full time roles are eligible for equity and benefits. Base pay is subject to change and may be modified in the future. Daresbury, United Kingdom £78,900—£92,900 GBP