Pertrice Bertet

Prof. Patrice Bertet from CEA Saclay and Université Paris-Saclay is awarded the IES Medal in Physics for his groundbreaking contributions to the quantum physics of electron spin resonance (ESR), including seminal observations of fundamental phenomena in spin resonance as well as profound technological developments in spin sensitivity. His pioneering results include the first observation of cavity-induced relaxation of spins, as originally predicted by Purcell in 1946, and most recently, the demonstration of single-spin pulsed ESR achieved using novel single microwave photon detectors. Bertet’s research is driven by pushing ESR spectroscopy into new domains and extremes, down to millikelvin temperatures. He has used Josephson parametric amplifiers to reach ESR sensitivity at the quantum limit of noise and employed vacuum-state squeezing to surpass these noise limits. By bridging quantum optics, superconducting circuits, and spin physics, Bertet has repeatedly redefined state-of-the-art ESR sensitivity through new paradigms for spin manipulation and detection. He has used these capabilities to study NV centers in diamond, dopants in silicon, and rare-earth ions in low-nuclear spin oxides, obtaining electron spin coherence times of tens to hundreds of milliseconds for near-surface spins. His sustained and transformative contributions to the field over the past 15 years make him a highly deserving recipient of this award.