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.

0:00:04 Introduction & guest overview

In this episode of ML4Q&A, hosts Chandana Rao and Patrick Geraghty speak with Professor Daqing Wang about his journey through experimental quantum science and the challenges of building cutting-edge quantum technologies. Wang reflects on his early experience contributing to a landmark experiment that demonstrated quantum teleportation over 143 kilometers between the Canary Islands, describing what it was like to join such a high-impact project as a master’s student and the practical challenges involved in detecting fragile quantum signals over long distances.

The conversation explores the realities of running demanding quantum optics experiments, from dealing with noise and imperfect equipment to designing reliable single-photon sources using molecules trapped in microcavities at cryogenic temperatures. Wang also discusses the importance of interdisciplinary collaboration, particularly between physicists and chemists, in identifying and engineering molecules suitable for quantum devices.

Looking ahead, the episode considers how new tools, including artificial intelligence, could help design better quantum materials and accelerate the development of future quantum technologies. The result is a wide-ranging discussion about the past, present, and future of experimental quantum research.

00:00:00 Intro

Michaela Eichinger, Product Solutions Physicist at Quantum Machines and quantum content creator, joins 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.

00:00:00 Intro

Jens Eisert joins ML4Q as a member for the next funding period which was granted around the time Chris and Mira recorded this Episode with him. So naturally, they discuss the German Excellence Initiative and how joining ML4Q was a natural step for Jens, given he has many previous and ongoing collaborations with other ML4Q members.

Jens shares his insights on various aspects of quantum information processing such as benchmarking and no-go theorems, his recent white paper on AI and quantum computing, quantum error correction, complexity and pseudo chaos. Ultimately Jens makes a convincing case that quantum computers remain fascinating "even if you confine yourself to saying things that are true". He reflects on the unwritten rules of academia, teaching and inspiring students, and his approach to finding research topics by looking for "cultural gaps" between fields.

00:00:00 - Intro

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.

00:00:00 Intro

In this episode of ML4Q&A, Chris and Mira talk with Alex Altland, theoretical physicist and ML4Q member, about the tension between deep scientific thinking and the administrative reality of coordinating the renewal proposal of ML4Q.

As one of the designated spokespersons for ML4Q’s next funding phase, Alex shares behind-the-scenes insights into managing this large-scale effort — just days before the final decision in May 2025.

We also explore his enduring fascination with foundational concepts in physics, spanning quantum field theory, quantum chaos, and topological matter. Alongside his research, Alex reflects on the importance of conceptual clarity in teaching, textbook writing, and his path from chemistry (and a brief detour into business consulting) to becoming a deeply theoretical physicist.

00:00:00 Intro

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!

00:00:00 Intro

In this special 20th episode of ML4Q&A, Chris and Mira celebrate the journey of the podcast, from its beginnings in 2021 to becoming a platform for exploring quantum careers, research, and innovation.

This milestone episode dives into the interplay between academia and industry in quantum technology with two distinguished guests: Jan Goetz, CEO and co-founder of IQM, and ML4Q Member, Frank Wilhelm-Mauch, researcher at Forschungszentrum Jülich and co-founder of Qruise. Together, they discuss the complementary roles of academia and industry in advancing quantum technology, shedding light on Europe’s pivotal role in the global quantum landscape.

Join us as we look back, celebrate the present, and dive into the future of quantum!

00:00:00 Intro

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.

00:00:00 Intro

In this episode, Mira and Chris talk with Markus Müller, a member of ML4Q and Professor at RWTH Aachen University and Forschungszentrum Jülich. Markus, an expert in quantum error correction, explains its importance in building large-scale quantum computers. He has supported pioneering logical qubit experiments on various platforms, including ion traps and superconducting qubits. They also discuss his recent work on avoiding mid-circuit measurements, a technique that benefits certain architectures and chip designs.

00:00:00 Intro