Compiler Optimization for Shuttling-Based Quantum Computing Architectures (COSMOS)

PhD position, Interdisciplinary Doctoral Program in Quantum Systems Integration at RWTH Aachen University


We are seeking after applicants for the PhD project

Compiler Optimization for Shuttling-Based Quantum Computing Architectures (COSMOS)

The goal of this project is to develop systematic support for compiling quantum software to computing architectures featuring qubit shuttling operations, which allow to dynamically reconfigure the quantum circuit between subsequent gate operations. They are common for quantum computing architectures based on semiconductor qubits, trapped ions, or neutral atoms. While there exists a large body of work for non-shuttling architectures, advanced compilation methods that allow to move qubits are rather scarce. We aim to provide a contribution to this field in the form of a systematic framework building on graph transformations, which will enable the use of classical compiler optimization techniques to be applied in a quantum setting. The resulting gain in algorithmic efficiency will accelerate the advent of applications on shuttling based architectures.

The project is a cooperation between the JARA-FIT Institute for Quantum Information and the Software Modeling and Verification (MOVES) Group at RWTH Aachen University and will be jointly supervised by Hendrik Bluhm and Thomas Noll. The expected starting date is early 2024.

How to apply

Please submit the following documents:

  • Letter of motivation explaining how you see your connection to the project
  • Curriculum vitae (including a description of your scientific background)
  • List of publications (if any)
  • Summary of your master’s thesis project (and possible connections to the position)
  • At least two letters of reference (please ask for the letters to be sent directly to us)
  • Certificate of master’s degree (if you do not have it yet, provide whatever confirmation you can get)
  • Transcript of records

All documents (except the recommendation letters) should be contained in a single PDF document. You should send your application ultimately by

September 30, 2023 (AoE)

via e-mail to Thomas Noll. Enquiries can also be directed to this e-mail address.

Required profile

Candidates must have (or soon obtain) a master’s degree in Computer Science, Physics, Mathematics, or a related area and have completed their studies with excellent grades. You should have interest in performing original, highly competitive scientific research, publishing your results in top conferences and scientific journals. Self-motivation and the ability to work both independently and as a team player in local and international research groups are expected. Fluency in English is required; proficiency in German is helpful but not compulsory.

What do we offer? We offer a stimulating international research environment, the possibility to participate in highly competitive and interdisciplinary research and the opportunity to involve students in your research through project work. Doctoral researchers have a status as employee with a salary according to the German federal employee scale TV-L E13; the exact salary is subject to your family situation. The duration of the position is four years.

RWTH Aachen University offers excellent facilities for professional and personal development. It is certified as a “Family-Friendly University”. We particularly welcome and encourage applications from women, disabled persons and ethnic minority groups, recognizing they are underrepresented across RWTH Aachen University. The principles of fair and open competition apply and appointments will be made on merit.

Research plan

The goal of this project is to conceive and implement a quantum compiler with full support of shuttling. The corresponding target systems are based on the SpinBus Architecture, which is being developed by the JARA-FIT Institute for Quantum Information in close cooperation between RWTH Aachen University and Forschungszentrum Jülich GmbH and is intended to be commercialized via the spin-off ARQUE Systems GmbH. It supports electron shuttling for semiconductor spin qubits. A focus of our work will be to leverage the large body of classical compiler optimization techniques to the optimization of shuttling moves. To this aim, we are planning to extend the ZX-Calculus to support moves, and make it amenable to the usage of optimizing graph transformations. The latter have a long-standing history in compiler construction as intermediate representations for (translated) code are often graph-based. The resulting performance will be compared to other approaches.

In a preparation phase, the candidate will familiarize themselves with the quantum hardware architecture and will derive required capabilities of a corresponding quantum compiler, with particular emphasis on shuttling operations. Next, a systematic framework based on existing software architectures for quantum computing systems will be established to formulate the hardware capabilities, performance parameters and transformations of quantum circuits in a flexible way. With regard to the latter, the extensibility of the ZX-Calculus to support shuttling moves will be assessed, and alternative approaches will be conceived if required. Moreover, a proof-of-concept compiler will be implemented as a prototype tool that supports the modeling and transformation framework. Finally, using this prototype implementation our approach will be benchmarked with respect to other methods and tools.