Quantum Technology Research at the RWTH Aachen University and Forschungszentrum Jülich
Much of our current technology, from semiconductor electronics to lasers, has emerged from what is sometimes referred to as the “first quantum revolution”, i.e., the understanding of the properties of matter based on the laws of quantum mechanics. More recently, elusive concepts of quantum mechanics such as superposition and entanglement ‑ which have long been regarded as puzzling curiosities of quantum mechanics with no practical purposes ‑ have become the keystones of several technological applications fostering the notion of a “second quantum revolution”.
These applications go from quantum sensing, to quantum simulations to quantum communications, and, last but not least, to quantum computing. The latter represents a paradigm shift in computing more fundamental than the evolution from the abacus to today’s supercomputers and promises unprecedented capabilities for certain computational tasks. Altogether, these different applications form the field of quantum technology.
The RWTH Aachen University boasts dedicated research groups to harness the exciting new opportunities presented by the current phase where quantum technology is moving from the mere academic research environment to be a primary topic of interest for industry and society.
Quantum Technology Group
The Quantum Technology Group is dedicated to the experimental investigation of semiconductor spin-qubits and to scanning SQUID spectroscopy.
The research effort on semiconductor spin-qubits is mostly based on gate-defined quantum dots in GaAs and SiGe, but it also explores other types of Si qubits and more “exotic” host materials for spin qubits, such as ZnSe. The goal is to assess the ultimate potential of these types of qubits as hardware for quantum computer and for quantum networking.
This effort is complemented by activities that tackle problems related to the scalability of qubit architectures, such as material growth homogeneity, device fabrication yield, the exploration of cryogenic qubit control systems and the development of efficient automated methods for tuning qubits.
The activity on scanning SQUID spectroscopy is based on a SQUID microscope operating at temperatures down to 20 mK and optimized for high frequency measurements. The high sensitivity of this instrument makes it a perfect tool for the investigation of quantum phenomena such as persistent currents, molecular magnets and surface spins.
The Quantum Technology Group is led by Prof. Hendrik Bluhm and Dr. Lars Schreiber, and it is part of the II. Institute of Physics.
Quantum Information - Theory
The theory groups led by Prof. David DiVincenzo, Prof. Fabian Hassler, Prof. Markus Müller, und Prof. Barbara Terhal pursue a variety of topics in both practical and fundamental quantum information science.
Solid-state quantum information processing devices, either based on spins or superconductors, are a real possibility for realizing a quantum computer. Majorana qubits might even have greater potential, although they still respresent a very young field of investigation. Our theoretical work aims at finding improved ways for these qubits to function and to work together in a system. This goal motivates very fundamental studies in a set of diverse areas, including many-body physics, the theory of quantum error correction codes, the theory of quantum control, and quantum computational complexity.
Researchers in the theory groups get to work on real-life problems in making quantum computers work, on designing new algorithms for the simulations of many-body quantum systems, and on working out the fundamental properties of quantum entanglement in a noisy world. They are involved in direct collaborations with researchers at the Jülich Research Center, with groups throughout Europe (e.g. Paris, Delft, Gothenburg, Zürich), and with established (e.g. IBM) and start-up organizations elsewhere in the world.
Quantum Information in Jülich
One of the long-term mission-projects of the Research Center Jülich is to contribute significantly to the development of a quantum computer. To this end, the Center is pursuing a broad portfolio of diverse research activities ranging from theoretical quantum information, to the large-scale simulation of quantum systems, to quantum optics and material science, and to the development of dedicated cryoelectronics for qubit control. As a joint initiative between Research Center Jülich and the RWTH Aachen University, the JARA Institute for Quantum Information is part of this development.
Major Collaborations
Matter and light for quantum computing (ML4Q)
Matter and Light for Quantum Computing (ML4Q) is a Cluster of Excellence funded in 2018 within the Excellence Strategy by the German Research Foundation (DFG).
It is a cooperation by the universities of Cologne, Aachen, and Bonn, as well as the Research Center Jülich. The aim is to develop the best hardware platform for quantum information technology, and to provide comprehensive blueprints for a functional quantum information network.
One of the strategic measures of the cluster is a novel Master study-track on Quantum Technology, starting from the winter semester 2019/20. It offers novel theory courses, advanced experimental labs, and cutting edge research projects in English. There’s financial support for outstanding students and bridging courses through preparatory Master’s College for international students. For more information, visit www.rwth-aachen.de/mscqt.
OpenSuperQ
Prof. DiVincenzo is member of the European FET Flagship project OpenSuperQ, which aims at designing, building and operating a quantum information processing system of up to 100 qubits and at sustainably making it available at a central site for external users.
Long-range quantum bus for electron spin qubits in silicon (Si QuBus)
JARA IQI participates to the QuantERA network with the project “Long-range quantum bus for electron spin qubits in silicon” (Si QuBus). QuantERA is a network of 31 organisations from 26 countries that supports international research projects in the field of Quantum Technologies (QT). QuantERA answers the growing need for collaborative endeavours and common funding schemes within QT research, which due to its highly interdisciplinary nature cannot be confined to an individual institution or state.
The goal of the Si QuBus project is to demonstrate a fault-tolerant quantum bus (QuBus) that coherently transfers a single electron with an arbitrary spin qubit state between quantum dots separated by 1 to 10 microns.
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