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Meeting ID: 935 8655 7757
Passcode: 008066

At the dawn of the 20th century, quantum mechanics replaced continuous descriptions of physical systems with discrete, quantized models. A notable example occurs in electromagnetism, where continuous waves become discrete packets of energy called photons. However, quantum effects generally appear only when a few excitations are present. For instance, in our everyday world, electromagnetic radiation involves vast numbers of photons, making light appear as continuous classical waves. This leads to a fundamental question: what is the largest object that can display quantum mechanical effects? While individual atoms and subatomic particles clearly show quantum behavior, superconductivity provides a remarkable pathway to macroscopic quantum phenomena, allowing large pieces of material (containing roughly 10^23 atoms) to act as a single coherent quantum entity. In the late 1980s, pioneers John Clarke, Michel Devoret, and John Martinis demonstrated that macroscopic superconducting circuits could exhibit quantized energy levels, absorbing distinct, countable numbers of photons like individual atoms. This surprising result was recently recognized with the 2025 Nobel Prize in Physics.

In this talk, I will discuss the major achievements of this groundbreaking work and explore the incredible array of technologies that have emerged from it, including quantum computing, ultra-sensitive amplifiers, and detectors, all arising from this pioneering demonstration of macroscopic quantum behavior.

Hosted by Professor Benoit Cushman-Roisin