The Light Side

What does it actually take to build a quantum computer?In this episode of The Light Side, we speak with Lia Yeh, a quantum computing researcher at the University of Cambridge, about quantum computer architecture, compilation, software and hardware, and the different approaches researchers are taking to build quantum machines.Lia explains how her background in computer science and physics led her to quantum computing, why the field has so many competing designs, and why computer science is playing a bigger role as quantum hardware develops.We also explore ZX calculus, a graphical language for representing and reasoning about quantum computation, and hear about Lia's experience teaching quantum computing to more than 200 high school students at a time.If you're curious about where physics, computer science and quantum computing meet, this episode is for you.In this episode:00:00–02:10 Lia’s path into physics and quantum computing02:10–03:55 Discovering computer science through teaching03:55–05:28 First experiences learning and teaching quantum computing05:28–07:05 Quantum computing in popular culture: fact vs. fiction07:05–10:37 Lia’s research focus: quantum architecture, compilation, and the computing stack10:37–13:39 What it looks like to use a quantum computer13:39–18:09 How the quantum-computing field has evolved and why it’s exciting now18:09–20:29 Teaching quantum computing around the world20:29–23:29 What ZX calculus is and why it matters23:29–26:37 ZX calculus compared with quantum circuits and measurement-based computation26:37–30:12 Research projects: connecting logical and physical quantum systems30:12–32:32 Growing use of ZX calculus32:32–38:00 Open questions in quantum computing: error correction, complexity, and quantum communication

What is it like to fall in love with a problem?In this episode I sit down with Professor David Deutsch, pioneer of quantum computing and one of the most influential thinkers in modern theoretical physics. David takes us through his journey from studying quantum fields in Dennis Sciama's prefab hut at Oxford to developing the theoretical foundations of quantum computing. We discuss Constructor Theory, a new framework he is developing with Chiara Marletto, that approaches physics through what can and cannot be caused to happen rather than predicting what will happen from initial conditions.If you are curious about what drives a lifetime of creativity in science, this conversation will stay with you.

Jocelyn Bell Burnell discovered pulsars as a Cambridge graduate student in 1967, but there's so much more to her story.She walks us through growing up in Northern Ireland, where an astronomy book that her father brought home from the library, hooked her completely. We also hear about her experiences navigating Cambridge as one of the few women in physics.We explore what questions excite her today and her hopes for the future of astronomy and science.

What exactly makes a quantum computer different from the laptop on your desk? In this episode, I sit down with Dr. Maria Violaris, a quantum physicist at Oxford, to discuss how qubits use superposition and entanglement, why today’s quantum computers are impressive but not yet practical, and the challenges researchers are working to overcome. Maria also shares her journey into quantum computing and what inspired her to explore this field.

Prof. Steve Simon from Oxford shares how he became fascinated with physics, unpacks topological quantum computing, and reflects on why history of science matters to him.