Theoretical Chemistry Seminar – Predicting and Controlling Correlated Light-Matter Interactions – Prof. Prineha Narang, Harvard University

Predicting and Controlling Correlated Light-Matter Interactions

Quantum systems host spectacular excited-state effects, but many of these phenomena remain challenging to control and, consequently, technologically under-explored. My research, therefore, focuses on how quantum systems behave, particularly away from equilibrium, and how we can harness these effects1. By creating predictive approaches to study dynamics, decoherence and photo-induced correlations in molecules and matter, our work could enable technologies that are inherently more powerful than their classical counterparts ranging from quantum information science, to ultra-high efficiency optoelectronic and energy conversion systems. In this talk, I will present work from my research group on describing, from first principles approaches, the microscopic dynamics, decoherence and optically-excited collective phenomena at finite temperature to quantitatively link predictions with 3D atomic-scale imaging, quantum spectroscopy, and macroscopic behavior. Capturing these dynamics poses unique theoretical and computational challenges. The simultaneous contribution of processes that occur on many time and length-scales have remained elusive for state-of-the-art calculations and model Hamiltonian approaches alike, necessitating the development of new methods in theoretical and computational quantum chemistry 2–4. I will introduce our work at the intersection of ab initio cavity quantum-electrodynamics and electronic structure methods to treat electrons, photons and phonons on the same quantized footing, accessing new observables in strong light-matter coupling. Building on this, I will show selected examples of our approach in ab initio design of active defects in quantum materials leveraging the chemical degree-of-freedom5–7 towards selectively linking these active defects 8–10. Finally, I will present an outlook on driving quantum chemical systems far out-of-equilibrium to control the coupled electronic and vibrational degrees-of-freedom 11–13.

References:

• Head-Marsden, K., Flick, J., Ciccarino, C. J. & Narang, P. Quantum Information and Algorithms for Correlated Quantum Matter. Chem. Rev. (2020) doi:10.1021/acs.chemrev.0c00620.
• Rivera, N., Flick, J. & Narang, P. Variational Theory of Nonrelativistic Quantum Electrodynamics. Phys. Rev. Lett. 122, 193603 (2019).
• Flick, J., Rivera, N. & Narang, P. Strong light-matter coupling in quantum chemistry and quantum photonics. Nanophotonics 7, 1479–1501 (2018).
• Flick, J. & Narang, P. Cavity-Correlated Electron-Nuclear Dynamics from First Principles. Physical Review Letters vol. 121 (2018).
• Narang, P., Ciccarino, C. J., Flick, J. & Englund, D. Quantum Materials with Atomic Precision: Artificial Atoms in Solids: Ab Initio Design, Control, and Integration of Single Photon Emitters in Artificial Quantum Materials. Adv. Funct. Mater. 29, 1904557 (2019).
• Hayee, F. et al. Revealing multiple classes of stable quantum emitters in hexagonal boron nitride with correlated optical and electron microscopy. Nat. Mater. 19, 534–539 (2020).
• Ciccarino, C. J. et al. Strong spin–orbit quenching via the product Jahn–Teller effect in neutral group IV qubits in diamond. npj Quantum Materials 5, 75 (2020).
• Neuman, T., Wang, D. S. & Narang, P. Nanomagnonic Cavities for Strong Spin-Magnon Coupling and Magnon-Mediated Spin-Spin Interactions. Phys. Rev. Lett. 125, 247702 (2020).
• Wang, D. S., Neuman, T. & Narang, P. Dipole-coupled emitters as deterministic entangled photon-pair sources. Phys. Rev. Research 2, 043328 (2020).
• Neuman, T. et al. A Phononic Bus for Coherent Interfaces Between a Superconducting Quantum Processor, Spin Memory, and Photonic Quantum Networks. arXiv [quant-ph] (2020).
• Juraschek, D. M., Meier, Q. N. & Narang, P. Parametric Excitation of an Optically Silent Goldstone-Like Phonon Mode. Physical Review Letters vol. 124 (2020).
• Juraschek, D. M., Narang, P. & Spaldin, N. A. Phono-magnetic analogs to opto-magnetic effects. Phys. Rev. Research 2, 043035 (2020).
• Juraschek, D. M., Neuman, T., Flick, J. & Narang, P. Cavity control of nonlinear phononics. arXiv [cond-mat.mtrl-sci] (2019).