Bernardi Research Group
Our group studies quantum interactions and dynamics in matter, addressing the microscopic processes that determine the properties of materials. Starting from quantum mechanics alone, with no input from experiments, we develop theory and computational methods that predict with high precision how electrons, atomic vibrations, spins, and other excitations interact and move in materials. This leads to quantitative predictions of transport properties, nonequilibrium dynamics, spin physics, and light-matter interactions. Our recent work further leverages machine learning and AI to accelerate these calculations and predict interactions and properties once beyond computational reach. We study materials ranging from the semiconductors of today's electronics to complex oxides and magnetic, topological, correlated, and atomically thin quantum materials. Our research addresses the basic science and materials physics from which the next generation of electronic, optical, magnetic, and quantum technologies will emerge.
Recent News
- Ramesh Dhakal receives the Caltech Presidential Postdoctoral Fellowship and joins the group. 7-1-26
- Yao Luo wins the Clauser Prize for best PhD thesis at Caltech. Congratulations! 6-15-26
- We receive funding from the Moore Foundation, Broadcom, and the Department of Energy for projects on understanding electron interactions and dynamics in quantum materials. 6-1-26
- Thomas Theiner receives the NSF Graduate Research Fellowship. Congratulations! 4-13-26
- We show a machine learning technique to compress phonon interactions and dramatically speed up their calculation. See the paper in Physical Review Letters and the story from Caltech News: New AI Technique Unravels Quantum Atomic Vibrations in Materials. 9-16-25
- We solve the polaron problem in real materials by developing first-principles diagrammatic Monte Carlo calculations. Read the article in Nature Physics and stories from Caltech news and Physics World. 7-15-25
- Marco gives an invited talk at the KITP on our recent work on strong coupling and compressing interactions in matter. The talk is available online on YouTube. 2-3-25
- We report a technique to compress electron-phonon interactions and greatly accelerate their calculation. Read the paper in Physical Review X and the story from Caltech News. 6-1-24
Recent Publications
- Strain-tunable spin relaxation in germanium from first principles.
Submitted. Preprint: arXiv 2608.31169 - Predicting electron-phonon coupling and electronic transport at the moire' scale in twisted bilayer graphene.
Submitted. Preprint: arXiv 2603.14800 - Transient absorption signatures of asymmetric carrier cooling in semiconductors.
Science Advances 2026 (accepted). - Efficient GPU parallelization of electronic transport and nonequilibrium dynamics from electron-phonon interactions in the Perturbo code.
Npj Computational Materials 2026 12, 257. - Magnetotransport in topological materials and nonlinear Hall effect via first-principles electronic interactions and band topology.
Physical Review Materials 2026 10, L031201. - Understanding polaronic transport in complex oxides by combining precise synthesis and first-principles many-body theory.
Reports of Progress in Physics 2026 89, 028003.
See Physics World How Polarons Travel through TiO2. - Magnon-phonon interactions from first principles.
Physical Review B 2025 112, L180403. - Tensor learning and compression of N-phonon interactions
Physical Review Letters 2025 135, 126101. - First-principles diagrammatic Monte Carlo for electron-phonon interactions and polaron
Nature Physics 2025 21, 1275.
