Industrial PhD position: Superconducting Qubit Control

Qubit control in superconducting circuits which involves, e.g., state preparation, gate operations, and readout, is implemented with microwave pulses. When scaling up for fault-tolerant quantum computing, the complex quantum mechanical systems must be able to correct for a multitude of error sources. Due to known and unknown characteristics of the quantum system, such as unwanted coupling, cross-talk, non-linearities, control signal overlap etc., errors will disturb the sensitive qubit states. It has been shown that leakage errors may be reduced significantly by careful design of the microwave signals to improve single-qubit and two-qubit gate fidelities, state preparation, and readout. Optimisation of the control signals is a crucial tool in moving towards fault-tolerant quantum computing that will require large qubit counts and high-fidelity operations.

Research project

This research project will be to study techniques to enhance the performance of QCs based on superconducting circuits by optimising the control system of the qubits. The research activities will focus on designing the microwave control signals. The optimal control routines will be experimentally tested and evaluated on state-of-the-art quantum computing devices.

Primarily, you will study techniques of waveform optimisation for the qubit control signals, such as hardware adaptive microwave pulse design. The goals of this research are novel methods that improve total fidelities by optimising the control of state preparation, logical gates, and state readout. The research outcome should support an accelerated development of large-scale, fault-tolerant QCs.

The project will balance both experimental and theoretical aspects of qubit control. On the one hand, pulse design requires detailed modelling of the quantum mechanical system dynamics, including multiple error sources and characteristics that are specific to the particular device. To validate the system models and estimate unknown model parameters, there will also be research activities regarding system characterisation on the experimental quantum computing device.

Your profile

You shall have strong background in mathematics and physics, for example a Master’s degree in Engineering Physics (Civilingenjör Teknisk Fysik), with an interest in modelling of and working experimentally with complex technical research questions. We believe that a Master’s level education in quantum mechanics is important.

You should be curious and excited to be working with new technologies and be comfortable working independently.

Particular merits for the position include:

• Experience in working with quantum computing technology and superconducting circuits
• Experience in working with experimentally with microwave systems
• Good communication skills, in direct communication and writing
• Experience in working with high level programming languages, such as Matlab or Python

This position requires that you pass a security vetting based on the current regulations around/of security protection. For positions requiring security clearance additional obligations on citizenship may apply.

About WACQT: Wallenberg Centre for Quantum Technology

WACQT is a 12-year research effort aiming at developing and securing Swedish expertise within quantum computing and simulation, quantum communications, and quantum sensing. A large part is devoted to develop a quantum computer that can solve problems far beyond the reach of the best conventional supercomputers.

Time: 2018 – 2030
Funder: Knut and Alice Wallenberg Foundation

Budget: 1.4 billion SEK plus cofounding
Universities: Chalmers University of Technology (coordinator), Lund University, KTH Royal Institute of Technology, Stockholm University, Linköping University, University of Gothenburg.

https://wacqt.se

What you will be a part of

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