Two postdocs in Quantum gate error reduction

Quantum gate error reduction – materials and circuit architectures for superconducting quantum computers, a collaboration between Chalmers University, Sweden and Aalto University, Finland. Come to the cutting edge of quantum technology – join our multi-talented, collaborative team working toward the common goal of building a 100-qubit quantum computer by 2025. You will be part of the most exciting things happening in this field, such as the Wallenberg Centre for Quantum Technology (WACQT) in Sweden, the Centre of Excellence Quantum Technology Finland (QTF), and the EU Flagship on Quantum Technology OpenSuperQplus.

Information about the project
The reduction of quantum gate errors represents the most important problem in the development of quantum computers in any technological platform. By this metric, superconducting qubits constitute a leading platform, with the best demonstrated two-qubit gate errors currently at the 0.1-0.2% level. Meaningful quantum computing requires that these errors be reduced to 0.01% in a scalable and reliable way across the multi-qubit chip. These gate errors are limited by decoherence and by systematic control errors, which we address in two postdoc projects.

The postdocs working on this collaborative project are expected to spend 50-75% of their time at Chalmers, with substantial research visits to Aalto. The project is funded for 2 years by WACQT with the possibility of a 5-month ramp-up phase in 2022 funded by QTF.

Major responsibilities
Position 1 - Optimal control pulses for quantum computers
In a superconducting quantum processor, quantum gates are realized by on-resonant or near-resonant microwave pulses with the intent of inducing Rabi oscillations on the desired qubit. However, standard Rabi pulses are not robust against errors in frequency and timing, and they are also not optimal with respect to leakage into higher excited qubit states.  The goal of this project is to use advanced methods in optimal control theory to accurately manipulate control pulses for generating both single and two-qubit gates.  The candidate is expected to develop these optimal control techniques and to experimentally demonstrate improvement of the  quantum gate fidelities of Chalmers quantum processors.

Position 2 - Reduced qubit decoherence by materials modeling, process development, and device characterization
Dielectric loss is the currently dominant decoherence mechanism in superconducting qubits (Burnett 2019). Other important contributions to decoherence originate from phonons and quasiparticles. Here we propose a joint experimental-theoretical study of decoherence at the level of the physics of the constituent materials by joining forces between Chalmers and Aalto. We foresee that this effort will drastically improve our understanding of the microscopic mechanisms of decoherence and its effect on our devices, which will directly help improve the design and process development of our devices already during the project. 

Qualifications
To qualify for the position of postdoc, you must hold a PhD in Physics, Applied Physics, Nanotechnology, or equivalent. You have expertise in experimental quantum computing, microwave quantum optics, or related fields in experimental physics. You are motivated for a career in quantum technology, be it in academia or at an institute or company. You have a collaborative attitude and an interest in working both independently and collaboratively in a team environment, sharing best practices and assuming responsibility. You are self-motivated, pay attention to detail, and possess a problem-solving analytical ability. You are willing to help supervise PhD students. The position requires sound verbal and written communication skills in English. 

Contract terms
This postdoc position is a full-time temporary employment for two years.

We offer
Chalmers offers a cultivating and inspiring working environment in the coastal city of Gothenburg. 
Read more about working at Chalmers and our benefits for employees.

Chalmers aims to actively improve our gender balance. We work broadly with equality projects, for example the GENIE Initiative on gender equality for excellence. Equality and diversity are substantial foundations in all activities at Chalmers.

Application deadline: May 31, 2022. 

Read more and apply here: https://www.chalmers.se/sv/om-chalmers/Arbeta-pa-Chalmers/lediga-tjanster/Sidor/default.aspx?rmpage=job&rmjob=10417&rmlang=SE



*** Chalmers declines to consider all offers of further announcement publishing or other types of support for the recruiting process in connection with this position. *** 
   



Chalmers University of Technology conducts research and education in engineering sciences, architecture, technology-related mathematical sciences, natural and nautical sciences, working in close collaboration with industry and society. The strategy for scientific excellence focuses on our six Areas of Advance; Energy, Health Engineering, Information and Communication Technology, Materials Science, Production and Transport. The aim is to make an active contribution to a sustainable future using the basic sciences as a foundation and innovation and entrepreneurship as the central driving forces. Chalmers has around 11,000 students and 3,000 employees. New knowledge and improved technology have characterised Chalmers since its foundation in 1829, completely in accordance with the will of William Chalmers and his motto: Avancez!