Title: Shaping Chemical Reactivity with the Quantum Vacuum: Ab Initio Advances in Polaritonic Chemistry via QEDFT
Abstract:
Can the quantum vacuum be used to control chemistry? Recent experiments in polaritonic chemistry suggest that it can: molecules placed inside optical cavities can exhibit altered reactivity, including site-selective and bond-selective transformations, even under collective coupling conditions where the microscopic mechanism remains deeply debated. Turning these observations into a predictive science requires a first-principles theory capable of treating electrons, nuclei, and quantized electromagnetic fields on equal footing, and of explaining cavity-modified chemistry without effective models or phenomenological assumptions.
In this talk, I will show how Quantum Electrodynamical Density Functional Theory (QEDFT) provides this missing ab initio framework. Rooted in the Pauli-Fierz Hamiltonian, QEDFT generalizes density functional theory to strongly coupled light-matter systems and makes it possible to predict how optical cavities reshape electronic structure, collective response, and chemical landscapes. A key message is that the quantum vacuum is not a passive background: vacuum fluctuations alone can drive qualitative changes in matter, induce new states, and open fundamentally new pathways for chemical control.
I will present two advances that sharpen this vision. First, we establish genuine ground-state quantum phase transitions driven entirely by vacuum fluctuations, demonstrating that cavity coupling defines a new axis for quantum materials design. Second, we show that the electronically dressed state emerging under collective vibrational strong coupling maps exactly onto the Sherrington-Kirkpatrick spin-glass model. This exact mapping uncovers frustration, disorder, and stochastic resonance as emergent microscopic ingredients of cavity-modified chemistry, and provides a concrete mechanism for local chemical transformations induced under collective coupling.
These results move polaritonic chemistry from intriguing phenomenology to predictive theory. More broadly, they open a rigorous route toward engineering chemical reactivity and novel material behavior by harnessing the quantum vacuum itself.
Biography:
Angel Rubio, born on 27 September 1965 in Oviedo, Spain, is Managing Director and Director of the Theory Department at the Max Planck Institute for the Structure and Dynamics of Matter (Hamburg). He is also Distinguished Research Scientist at the Simons Foundation Flatiron 2 of 5Institute (NY, USA), Professor/Chair for Condensed Matter Physics at the University of the Basque Country (Donostia-San Sebastián), Full Professor at the University of Hamburg, and External Scientific Member of the Fritz Haber Institute (Berlin). He received his PhD in Physics in 1991 from the University of Valladolid and was a postdoctoral researcher at the University of California, Berkeley (1992–94). Rubio is a pioneer of computational materials physics and a founder of modern theoretical spectroscopy, and the originator of the widely used open-source ab initio code Octopus. He created quantum electrodynamical density functional theory (QEDFT), established polaritonic chemistry and cavity materials engineering as rigorous first-principles disciplines, and introduced the Endyon quasiparticle as a unifying concept for vacuum-field renormalization of matter — contributions that have opened new fields at the intersection of quantum optics, chemistry, and condensed matter physics. His work spans excited-state theory, non-equilibrium light-driven phases, and moiré quantum matter, consistently delivering experimentally verified predictions for complex quantum systems. He has published over 700 papers with more than 90,000 citations (h-index 146).
His work has been recognized by the Spanish National Physics Prize "Blas Cabrera" (2023), the Max Born Medal (2018), the Gold Medal of the Spanish Royal Physical Society (2016), the Premio Jaime I for Basic Research (2014), the DuPont Prize in Nanotechnology (2006), the Friedrich Wilhelm Bessel Research Award of the Humboldt Foundation (2005), and multiple ERC Advanced Grants. Rubio is a Fellow of the American Physical Society, the European Physical Society, and the AAAS; a member of the Academia Europaea, the Leopoldina, and the European Academy of Sciences; and a Foreign Member of both the U.S. National Academy of Sciences and the Chinese Academy of Sciences.
LOCATION:Pfizer Lecture Hall STATUS:CONFIRMED DTSTART:20260514T201500Z DTEND:20260514T214500Z END:VEVENT END:VCALENDAR