effzett 1-22: Cool calculators

We are happy to announce that we are in the newest issue of the effzett 1-22 magazine.

Find out more about our work in the quantum computer and chip field at ZEA-2. Jülich researchers are developing so-called cryo-electronics that control qubits. Why and how they do it is explained in the current issue of effzett.

You can download it here: https://www.fz-juelich.de/en/press/effzett-forschen-in-juelich/icy-machines

Physicist Carsten Degenhardt and his team at Jülich's ZEA-2 are developing integrated nano- and microelectronic systems - including cryo-electronics for quantum computers. Electrical engineer Patrick Vliex designed the prototype for the new cryochip.

Minus 273 degrees Celsius – colder than anywhere in the universe. Classical electronic systems are not designed for this extreme cold. However, this is supposed to change. Jülich researchers are working on microchips that function without interference in these frosty conditions. They are to control the computers of the future: quantum computers with millions of qubits that only work at such temperatures.

“This works with 50 qubits, which is what quantum computers from IBM and Google use today, for example, or even with 100 qubits, but not for quantum computers in ten years’ time or more, which are expected to have over a million qubits,”

says Dr. Carsten Degenhardt from the Jülich Central Institute for Engineering, Electronics and Analytics (ZEA-2), convinced.

"In a few years, we could be in the same position with quantum computers as were the operators of conventional computing systems in the late 1950s."

Back then, engineers were designing ever more complex circuits to increase the computing power of computers: solder joints and the wiring of the individual components to one another were increasing to such an extent that both the space required and the probability of connection errors rose enormously. The situation could turn out similarly with qubits: the more there are to be
controlled, the more wires will be needed. This is not only a problem of space. The wires are prone to interference; the more wires, the more interference. Furthermore, the wires give off heat, which seeps into the cryostat – poison for the qubits, which need the cold.

Five years ago, therefore, the experts at ZEA-2 began working on their own chips. First, it was necessary to clarify the special requirements that a quantum processor presents to such a chip. For this purpose, the ZEA-2 team contacted the physicists led by Prof. Hendrik Bluhm at the JARA Institute for Quantum Information. Bluhm is working on a “Made in Germany” semiconduc-
tor quantum processor in the QUASAR project. Close cooperation developed between the JARA researchers, especially René Otten, and ZEA-2.

"Together we determined, for example, the level and increments of the voltages that the
chip is supposed to generate, plus the maximum electrical power acceptable for it to consume to achieve this without heating up the qubits too much. These are the basics for a circuit diagram,"

says Dr.-Ing. Patrick Vliex, who is responsible for designing the prototype at ZEA-2.