Work at the interface

A new professor arrived at the Institut quantique in 2018: Professor Max Hofheinz. Born in Germany, the professor in the Electrical and Computer Engineering Department obtained a degree in physics from the University of Karlsruhe, which is located about 80 km northwest of Stuttgart.

“I spent three years in Germany, and then I took part in an exchange program between Karlsruhe and Grenoble. I thought I would probably lose the French I had learned in school if I didn’t use it more. I completed a postgraduate degree in physical engineering and another in microelectronics in France,” explains Professor Hofheinz.

The Two Cultures

As a graduate student, he was interested in silicon transistors, a topic that was quite close to the work of Professors Eva Dupont-Ferrier and Michel Pioro-Ladrière. As a postdoctoral fellow in the group of Professors John Martinis and Andrew Cleland at the University of California in Santa Barbara, Professor Hofheinz focused his research on superconducting circuits, qubits and microwave resonators.

His current project took shape during a second postdoctoral fellowship in Saclay. In brief, it involves a different use of the Josephson junction, the key component of superconducting qubits. Although it is usually used as a nonlinear inductance, in the Josephson photonics he is working on, it becomes an active component capable of generating microwave photons. He wishes to make them devices at the intersection between the classical world and qubits that would be easier to use, faster and able to operate at higher frequencies.

 How does one go from Grenoble to Sherbrooke?

“There is already a collaboration between Grenoble and Sherbrooke, and I knew the university through Professors Blais, Reulet, Poulin and Pioro-Ladrière, who have undeniable notoriety in our field. After two or three visits, I discovered a wonderful atmosphere with an approach that promotes the pooling of expertise through its connection with engineering. In addition to this expertise, 3IT (Institute for Interdisciplinary Innovations in Technology) is available for manufacturing, which makes it a complete professional environment. My main efforts to integrate myself have been temperature-related: I needed to get used to temperature shifts of 30 degrees in 24 hours. Even if it is a lower order of magnitude, we still have to undergo thermal shocks like what we are doing to our samples.”

As a research institute that is located at the intersection of quantum materials, quantum information and quantum engineering, Professor Hofheinz’s knowledge base perfectly aligns with the IQ’s objectives.