ML4Q&A - from the lives of quantum physicists

In this episode of ML4Q&A, hosts Chandana Rao and Mira Sharma speak with Dr. Lars Schreiber (RWTH Aachen University), along with his PhD students Mats Volmer and Max Beer, about the challenges of scaling silicon-based spin qubit quantum computers. Lars Schreiber shares insights into why semiconductor platforms despite their technological maturity have not yet achieved large-scale quantum systems. The conversation explores the practical realities of building spin qubit devices, from material imperfections and device variability to the difficulty of controlling millions of qubits. Mats and Max discuss their work on conveyor-style spin-qubit shuttling and T-junction architectures for routing qubits in two dimensions, explaining how moving electrons across a chip can enable scalable designs while introducing new challenges such as valley splitting and decoherence. They also discuss the surprising material physics that emerges when quantum informations starts to move. The episode also examines how these research ideas are transitioning into real-world technology through the startup Arque Systems, highlighting the shift from academic prototypes to industrial-scale quantum hardware. Listen to the full episode to explore the path toward scalable semiconductor quantum computing.

Michaela Eichinger, Product Solutions Physicist at Quantum Machines and quantum content creator, joins Mira and Chris on ML4Q&A to discuss her journey from academic research to working in a deep-tech startup. She is representative of a generation of PhD students and postdocs from labs working on qubit technologies that join the emerging quantum industry. Her PhD work focused on gatemons and stencil-based nanofabrication of superconducting qubits at the Niels Bohr Institute. Now she works at Quantum Machines, a company developing control electronics for quantum computers that aims to provide hardware capable of meeting the demands of fault-tolerant quantum architectures. In this episode, Michaela reflects on the 2025 Nobel Prize, talks about cleanroom and measurement challenges during her PhD, and compares writing papers with writing patents. She explains her role at Quantum Machines and the company’s mission to harness FPGAs—the key electronic component—to control qubits on nanosecond timescales. In addition to synthesizing control pulses and processing readout signals, intricate classical computations must be performed in real time, for example to track qubit errors to correct them on the fly. Despite growing sophistication these advanced electronic products must remain easy to deploy. She also discusses the importance of science communication, which led her to launch a newsletter to help educate a broad audience about the latest breakthroughs and explain key ideas in quantum computing. Whether you are an aspiring quantum researcher or simply curious about the state of the quantum industry, this episode conveys the excitement of living on this technological frontier.

In this episode of ML4Q&A, host Mira Sharma, an associated member of the Matter and Light for Quantum Computing (ML4Q) Cluster, chats with one of the leading voices in experimental quantum optics - Professor Christine Silberhorn from the University of Paderborn. Christine’s groundbreaking work in integrated quantum optical systems has earned her numerous prestigious awards. She’s also a member of the Academy of Sciences and Arts of North Rhine-Westphalia and was appointed to the German Science Council in 2023. Her research focuses on making photonic quantum computing scalable and practical - using light particles, or "flying qubits," to push the boundaries of quantum communication. In this conversation, Christine shares how photonic quantum systems can be integrated on a chip, why education in quantum science needs fresh thinking as well as her personal journey in academia and research.

In this episode of ML4Q&A, Chris and Mira are joined by ML4Q Professor Mario Berta, who shares his unique journey from ETH Zürich via Imperial College London and Amazon Web Services to RWTH Aachen University. They discuss his work on quantum algorithms, benchmarking, and bridging the gap between theory and industry, as well as insights into starting a research group and teaching theoretical physics. Tune in to explore Mario’s fascinating career path and hear about the quantum version of Stein’s Lemma!

In this episode, Mira and Chris speak to Sebastian Hofferberth about his journey through academia as he literally went from Heidelberg to Harvard, to Stuttgart, then Denmark and finally to Bonn where he became member of ML4Q. We talk about the challenges of this nomadic lifestyle, which almost every longtime academic faces. Of course, Sebastian also explains his work in quantum optics with Rydberg atoms and shares his passion for teaching. He discusses how quantum mechanics (can be) seems non-intuitive at first but can be made more approachable.

In this episode Mira and Chris talk to Silvia Pappalardi, who joined ML4Q as a junior professor last April. Silvia heads the Qhaos group (spelled with a Q) and introduces our listeners to the topic of quantum chaos which might be a bit intimidating for many of us. So, join Chris and Mira as they get some intuitive explanations from Silvia about concepts like thermalization and ergodicity and understand how these concepts relate to entanglement.

In this episode Chris talks to Gláucia Murta, a postdoc in ML4Q, who was won the cluster's Young Investigator Award. They talk about Gláucia’s passion for fundamental questions, device independence and a great outreach project, the podcast O Q Quantico she just launched in her home country, Brazil.

In this episode Chris talks to Steven Koester, Professor of Nanotechnology in the Department of Electrical and Computer Engineering at the University of Minnesota. Steve - who is our first external guest on the podcast - is joining us mainly as the Director of the Global Quantum Leap program – a network of networks including ML4Q - which provides an essential linkage between the fields of nanofabrication and quantum information sciences on an international level. They talk about his electrical engineering background, how he got a first taste of quantum devices during his Masters studies at Notre Dame, eventually leading to his PhD work on indium arsenide. They also discuss his industry experience working at IBM. But as a main topic, he introduces the Global Quantum Leap program and the cultural exchange it fosters in order to tackle big global challenges as in the field of quantum computing.

In this episode, we talk to David DiVincenzo, Director of the Institute of Theoretical Nanoelectronics at Forschungszentrum Jülich & co-founder of the Institute for Quantum Information which is a joint institute of RWTH Aachen and the Forschungszentrum. We start by listening to David's take on different aspects of the fast developments in the field of quantum computing. Then, we take a deep dive into the mid eighties and early ninties and discuss how David started working on quantum computing before Shor’s algorithm and quantum error correction were discovered. Naturally then, him and his collaborators at IBM were ready to contribute to the developing field. We touch upon the DiVincenzo criteria and the Loss-DiVincenzo quantum dot proposal and get to know some of the mentors David was lucky to have had.

In our new season we feature members of the cluster who are working at the intersection to other stakeholders in the larger quantum community. In this episode, we talk to Tommaso Calarco, Director of the PGI Institute for Quantum Control at Forschungszentrum Jülich, professor for Theoretical Physics at the University of Cologne and member of ML4Q. We discuss how he started working on apparently useless science which soon turned out to be the future of quantum. We also talk about many synergies: between theory and experiment, science and government as well as academia and rising startups in the field.

We continue to feature some of our experimental physicists. In this episode, we talk to Annika Kurzmann, Junior Principle Investigator at RWTH Aachen and associated member of ML4Q. We talk abour her work on optical quantum dots during her PhD and bilayer graphene quantum dots in her postdoc and how she is now bringing this together to detect single electron dots in graphene. We also discuss the Ruhrgebiet, tenure tracks and starting a lab during the pandemic.

We now move on to feature some of our experimental physicists and we start with Rami Barends, recently appointed head of the Institute for Functional Quantum Systems at Forschungszentrum Jülich and associated member of ML4Q. We will talk about his research on superconducting circuits and the long way from his PhD work on superconducting detectors for astrophysics to demonstrating beyond classical computation with superconducting qubits at Google. We will talk about research in the university versus research at Google and his plans for setting up his new group at the Institute for Functional Quantum Systems. Visit https://ml4q.de/ml4qa/ for more podcast episodes Visit https://ml4q.de/stories/ for more stories from our researchers at ML4Q Follow us on twitter: https://twitter.com/ML4Q_cluster Visit Beata's group site: https://pgi-jcns.fz-juelich.de/~kardynal/ and contact her via E-mail: r.barends(at)fz-juelich.de Host: Christian Dickel Music: Technology by Keys of Moon | https://soundcloud.com/keysofmoon Music promoted by https://www.free-stock-music.com Attribution 4.0 International (CC BY 4.0) https://creativecommons.org/licenses/by/4.0/ Discovery by Scott Buckley | https://soundcloud.com/scottbuckley Music promoted by https://www.free-stock-music.com Attribution 4.0 International (CC BY 4.0) https://creativecommons.org/licenses/by/4.0/ Title: Lunar Levitation Artist: Aakash Gandhi

In a new podcast episode of ML4Q&A, Kathrin Dorn (PhD student, Egger group) speaks to Dagmar Bruss, professor at the Institute for Theoretical Physcs III in Düsseldorf. They talk about Dagmar's passion about quantum information theory, how a coffee break in Oxford changed her research focus to quantum key distribution, her experience with the impostor phenomenon and how she got involved in a supercosmos project in astronomical technology. 00:00 intro 01:35 from astronomical technology to quantum information 06:23 working at ISI in Turin and joining talks by Grover and Shor 08:10 from experiment to theory 10:38 how is your working day? 14:43 struggles and experiencing the impostor phenomenon 19:24 work on quantum key distribution 25:27 ongoing work in ML4Q 32:28 1 or 2? Visit https://ml4q.de/ml4qa/ for more podcast episodes Visit https://ml4q.de/stories/ for more stories from our researchers at ML4Q Follow us on twitter: https://twitter.com/ML4Q_cluster Visit the homepage of Dagmar's institute: https://www.tp3.hhu.de/en/ Contact Dagmar via E-mail: dagmar.bruss(at)uni-duesseldorf.de Host: Kathrin Dorn Music: Technology by Keys of Moon | https://soundcloud.com/keysofmoon Music promoted by https://www.free-stock-music.com Attribution 4.0 International (CC BY 4.0) https://creativecommons.org/licenses/by/4.0/ Discovery by Scott Buckley | https://soundcloud.com/scottbuckley Music promoted by https://www.free-stock-music.com Attribution 4.0 International (CC BY 4.0) https://creativecommons.org/licenses/by/4.0/ Title: Lunar Levitation Artist: Aakash Gandhi