Quantum Computing Systems (QCS)

An initiative based at the Department of Information Technology, Uppsala University.
Founded by Ramanathan Thinniyam Srinivasan, October 2025.

We are laying the foundations for a full-stack quantum computing ecosystem at Uppsala University — by developing core expertise in systems, theory, and verification, and by collaborating across divisions to expand into emerging domains such as quantum control, machine learning, and applications.

⚛️ What is Quantum Computing?

Quantum computing is the study of how information can be represented and processed using the principles of quantum mechanics. It is a new computational paradigm — not just classical simulation of quantum phenomena.

Quantum computing ≠ Classical computing about quantum systems.
While much classical research focuses on using conventional computers to simulate physical systems like molecules or materials, quantum computing builds entirely new machines — based on quantum primitives such as qubits, unitary gates, and quantum measurements.

This paradigm shift enables radically new forms of computation, grounded in superposition, entanglement, and interference — allowing us to solve certain problems faster than any classical algorithm can.

At QCS, we view quantum computing through the lens of the quantum computing stack:

Quantum Hardware: Architectures based on superconducting circuits, trapped ions, photonics, neutral atoms, and spin qubits.
Quantum Software: Languages, compilers, transpilers, and error correction frameworks that map high-level descriptions to real hardware (e.g., Qiskit, Cirq, Stim).
Quantum Algorithms: Algorithms such as Shor’s factoring and Grover’s search that provide exponential or quadratic speedups over classical methods.
Quantum Verification: Formal methods (from automata, logic, model checking) adapted to ensure correctness, reliability, and robustness of quantum programs and circuits.

These layers form a coherent and rigorous computational stack — not unlike the classical computing ecosystem — and require deep computer science foundations.

Our perspective is simple but important: Quantum computing is still computing. It is not a subfield of physics, but a full-fledged computational discipline — asking core questions like:
What is a computation? What can be computed efficiently? How can we verify correctness?

🧩 Current Focus: Verification of Quantum Programs

At QCS, our current focus lies in Quantum Program Verification (QPV) — the challenge of reasoning formally about the correctness of quantum algorithms and circuits.

We approach this problem using tools from automata theory and logic, drawing on decades of expertise in classical verification from the Division of Computer Systems (DoCS) at Uppsala University.

Our recent work includes a POPL 2026 paper on verifying quantum circuits using weighted tree automata, becoming one of the first efforts to enable parametrised verification (i.e. the ability to verify entire families of circuits in one shot). This work is in collaboration with researchers in Taiwan and the Czech Republic.

🎯 Mandate and Vision

The mission of QCS is twofold:

Develop foundational quantum computing expertise in the Core Areas — quantum analogues of classical research strengths in the DoCS and CSD divisions of the Department of Information Technology.
Foster collaborations with other divisions to help them engage with quantum computing in their own domains (Allied Areas) — including control, machine learning, scientific computing, and applications.

Our long-term vision is to create a robust quantum research ecosystem within the Department of Information Technology — aligned with our classical strengths and outward-looking toward collaboration and growth.

Core Areas

Quantum Program Verification (QPV): reasoning about the correctness of quantum algorithms and circuits using formal methods from automata theory and logic.
Quantum Computational Models and Complexity (QCC): studying formal models of quantum computation and their relationships to classical models; understanding quantum speedups and limits through complexity-theoretic frameworks.
Quantum Compilation and System Architecture (QCSA): building compilers, intermediate representations, and architecture-aware optimizations for mapping quantum algorithms to real hardware; includes circuit rewriting, gate synthesis, and hardware-specific transpilation.
Quantum Communication and Networking (QComm): designing quantum protocols for secure communication and distributed quantum computation.

Allied Areas

Quantum Cryptography and Post-Quantum Security (QCrypt): developing cryptographic methods secure against quantum adversaries; includes post-quantum cryptography, quantum-resistant algorithms, and quantum authentication protocols.
Quantum Machine Learning (QML): developing hybrid quantum-classical algorithms for tasks such as classification, regression, and optimization; examples include variational quantum algorithms.
Quantum Control and Hardware Abstraction (QControl): designing and analyzing control strategies for low-level manipulation of quantum systems.
Quantum Applications in Science and Engineering (QApps): applying quantum algorithms to simulate physical, chemical, and biological systems; domains include quantum chemistry, condensed matter physics, and materials science.

📬 Mailing Lists

We coordinate our activities through two mailing lists — open to different levels of involvement:

QCS Community List: For anyone at Uppsala University interested in quantum computing — including events, talks, and general announcements.
👉 To join, subscribe to quantum-computing-it@lists.uu.se from your UU email address.
QCS Research List: For researchers at the department who are actively publishing in the field.
👉 Baseline criterion: at least one accepted or published paper in a computer science venue with “quantum” in the title.
👉 Note: Meeting the technical bar does not guarantee membership — the QCS group is a curated research team. Inclusion is by invitation, based on active collaboration, strategic alignment, and mutual trust.
👉 If you meet the bar and are interested in joining QCS, contact ramanathan (dot) s (dot) thinniyam (at) it (dot) uu (dot) se with a link or reference to your paper(s).

👥 Group

Contact person (For seminar coordination, inquiries, or collaboration):

Ramanathan Thinniyam Srinivasan, Assistant Professor, Division of Computer Systems, Department of Information Technology.

Members:

Philipp Ruemmer, Associate Professor, Division of Computer Systems, Department of Information Technology.
Parosh Aziz Abdulla, Professor, Division of Computer Systems, Department of Information Technology.