Ab initio approaches to correlated light-matter interactions

Prineha Narang (Harvard University)

ABSTRACT: 

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. 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 physics 2–6. This pedagogical talk will introduce existing ab initio approaches to capture such correlated light-matter interactions. Next, 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. Current approximations in the field almost exclusively focus on electronic excitations, neglecting electron-photon effects, for example, thereby limiting the applicability of conventional methods in the study of quantum chemical and polaritonic systems, which requires understanding the coupled dynamics of electronic spins, nuclei, phonons and photons. With our approach we can access correlated electron-photon and photon-phonon dynamics.  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-freedom7–9 towards selectively linking these active defects 10–12. 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 13,14 and a pathway to link these with transport in materials15,16.

References:

  1. 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.
  2. Rivera, N., Flick, J. & Narang, P. Variational Theory of Nonrelativistic Quantum Electrodynamics. Phys. Rev. Lett. 122, 193603 (2019).
  3. Flick, J., Rivera, N. & Narang, P. Strong light-matter coupling in quantum chemistry and quantum photonics. Nanophotonics 7, 1479–1501 (2018).
  4. Flick, J. & Narang, P. Cavity-Correlated Electron-Nuclear Dynamics from First Principles. Physical Review Letters vol. 121 (2018).
  5. Schäfer, C., Flick, J., Ronca, E., Narang, P. & Rubio, A. Shining Light on the Microscopic Resonant Mechanism Responsible for Cavity-Mediated Chemical Reactivity. arXiv [quant-ph] (2021).
  6. Wang, D. S., Neuman, T., Flick, J. & Narang, P. Light-matter interaction of a molecule in a dissipative cavity from first principles. J. Chem. Phys. 154, 104109 (2021).
  7. 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).
  8. 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).
  9. 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).
  10. 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).
  11. Wang, D. S., Neuman, T. & Narang, P. Dipole-coupled emitters as deterministic entangled photon-pair sources. Phys. Rev. Research 2, 043328 (2020).
  12. Neuman, T. et al. A phononic interface between a superconducting quantum processor and quantum networked spin memories. npj Quantum Information 7, 1–8 (2021).
  13. Juraschek, D. M., Meier, Q. N. & Narang, P. Parametric Excitation of an Optically Silent Goldstone-Like Phonon Mode. Physical Review Letters vol. 124 (2020).
  14. Juraschek, D. M., Narang, P. & Spaldin, N. A. Phono-magnetic analogs to opto-magnetic effects. Phys. Rev. Research 2, 043035 (2020).
  15. Vool, U. et al. Imaging phonon-mediated hydrodynamic flow in WTe2. Nat. Phys. 1–5 (2021).
  16. Varnavides, G., Jermyn, A. S., Anikeeva, P., Felser, C. & Narang, P. Electron hydrodynamics in anisotropic materials. Nat. Commun. 11, 1–6 (2020).

RECOMMENDED PAPER:

Quantum Information and Algorithms for Correlated Quantum Matter

https://pubs.acs.org/doi/10.1021/acs.chemrev.0c00620

BIO:

Prineha Narang is an Assistant Professor at the John A. Paulson School of Engineering and Applied Sciences at Harvard University. Prior to joining the faculty, Prineha came to Harvard as a Ziff Fellow at HUCE and worked as a Research Scholar at MIT. She received an M.S. and Ph.D. in Applied Physics from the California Institute of Technology (Caltech). Prineha’s work has been recognized by many awards and special designations, including a Friedrich Wilhelm Bessel Research Award from the Alexander von Humboldt Foundation, a Max Planck Sabbatical Award from the Max Planck Society, and the IUPAP Young Scientist Prize in Computational Physics in 2021, an NSF CAREER Award in 2020, being named a Moore Inventor Fellow by the Gordon and Betty Moore Foundation for pioneering innovations in quantum science, CIFAR Azrieli Global Scholar by the Canadian Institute for Advanced Research, and a Top Innovator by MIT Tech Review (MIT TR35). Outside of science, she is an avid triathlete and runner.