Two postdocs in fabrication and characterisation of Josephson field-effect transistors for quantum computing - Hiring in process/Finished, not possible to apply

Electrification, digitalisation and health technology are among the largest areas for the future in the conversion to sustainable societies. The Department of Electrical Engineering at Uppsala University in Sweden, conducts successful research and education in the areas – renewable energy sources, electric vehicles, industrial IoT, 5G communication and wireless sensor networks, and smart electronic sensors and medical systems. The Department of Electrical Engineering is an international workplace with around 140 employees that all contribute to important technical energy and health challenges at the Ångström Laboratory.

The positions will be placed at the Division of Solid-State Electronics, the Department of Electrical Engineering. Each position is meant for two year, with the possibility to extend for one year.

The research at the Division of Solid-State Electronics has three major focus areas: Electronics for Life Science and Medical Technologies, Electronics for Renewable Energy and Electronics for Next-Generation Computing. The technological base for our research is thin-film technology, semiconductor processing and semiconductor device technology using the in-house state-of-art cleanroom facilities, supported by device and process simulation as well as advanced electrical and optical characterisation. Our research objective is to develop technological solutions, from devices to small systems, for comprehensive analysis of genome, proteome, and transcriptome signatures of individuals, thereby enabling AI assisted predictive diagnosis and preemptive therapy. We strive for innovations such as near-body-network systems, point-of-care electronic sensors and battery-free wearable and medical systems for continuous and real-time health monitoring. Such systems require mechanically flexible and soft devices including electronic and optoelectronic components, supported by thermoelectric or triboelectric/piezoelectric generators. Our research on renewable energy spans from nanophononics and hybrid materials for thermoelectrics to energy-efficient electronics. Finally, we have lately renewed our efforts to harness novel materials and electronic device solutions towards a new computing paradigm wherein quantum and neuromorphic electronics play a crucial role.

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Project description
Quantum technology for quantum computing builds on a deep understanding of the fundamental phenomena underlying the quantum properties as well as of the phenomena limiting the qubit performance. The chosen materials and integration technology need to offer a real potential of scalability and reproducibility, as in the case of CMOS compatible materials including silicon and CMOS process technology. The aim of our new collaborative European QuantEra project (with partner groups in France and Hungary) is to realise and study a Si gatemon qubit, a gate tuneable transmon qubit composed of a Si Josephson field-effect transistor (JoFET) coupled to a microwave resonator. It represents a valid integrable and scalable alternative to fully metallic superconducting qubits.

The project at Uppsala University will focus on the Si JoFET, i.e., a Si transistor with superconducting source and drain (S&D) contacts, whose non-dissipative supercurrent can be modulated by an electrostatic gate. CMOS-compatible superconductors including metal silicides will be used as the superconducting S&D contacts. A comprehensive investigation of the superconductor/Si (S/Sm) interface by means of structural, chemical and low-temperature electronic transport characterisation will be performed. The first and foremost objective is to optimise the S/Sm interface transparency so as to allow for the transfer of correlated charge carriers from the superconducting contacts into the Si channel and to reach large, reproducible supercurrents. The second objective is to realise Si JoFETs, demonstrating the gate tuneability of the Josephson supercurrent. Thereupon, the third and final objective is to integrate Si JoFETs in a transmon geometry including on-chip capacitors and resonators, and to realise the manipulation of quantum states in Si-gatemon devices.

Duties

• Design and fabrication of test circuits for study of the S/Sm interface based on standard silicon technology in the cleanroom laboratory of Myfab-Uppsala.
• Design and fabrication of JoFETs by integrating the optimised S/Sm contact structure.
• Characterisation of the test circuits and JoFETs by both physical means such as SEM, TEM, and electrical methods down to liquid helium temperature (4.2 K).
• Simulation, based on commercial software packages, for assistance in device design as well as in interpretation of characterisation results.
• Collaboration with partner groups in electrical characterisation down to mK, quantum physics, simulation and TEM characterisation.

Requirements

• The applicant must hold a Doctoral degree in Technical Physics, Electrical Engineering and / or Materials Science with a focus on semiconductor processing and electronics, or a foreign degree that is deemed to correspond to such degrees.
• The degree needs to be obtained by the time of the decision of employment. Those who have obtained a PhD degree three years prior to the application deadline are primarily considered for the employment. The starting point of the three-year frame period is the application deadline. Due to special circumstances, the degree may have been obtained earlier. The three-year period can be extended due to circumstances such as sick leave, parental leave, duties in labour unions, etc.
• Experience, supported by scientific publications, in silicon technology, device fabrication and characterisation, modelling/simulation.
• Very good oral and written proficiency in English.

We put an emphasis on your personal qualities such as good collaboration and communication skills with other researchers. You should be purposeful, structured and able to work effectively both individually and in groups.

Application
Please send your application materials to Prof. Shi-Li Zhang (see below for contact info). You should include a brief description of your research interests and relevant experience, a CV, copies of diplomas and certificates, thesis (or a draft thereof) and other relevant documents. You are encouraged to provide contact information to reference.

About the employment
The employment is a temporary position of two years according to central collective agreement. Employment 100 %. Starting date 2022-04-01 or according to agreement. Placement: Uppsala.

For further information about the position, please contact: Professor Shi-Li Zhang, telephone +46 18-471 7247, shili.zhang@angstrom.uu.se.

Please submit your application by March 31th 2022, UFV-PA 2022/64.

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