Quantum Information Perspective on the Ground State Problem: What is Electron Correlation?

Speaker: Dr Christian Schilling, University of Geneva, Department of Physical Chemistry
Series: Theory - Chemistry Research Interest Group

Describing strongly interacting electrons is one of the crucial challenges in the modern quantum sciences. A comprehensive solution to this electron correlation problem would simultaneously exploit both the pairwise interaction and its spatial decay. By taking a quantum information perspective, we explain how this structure of realistic Hamiltonians gives rise to two conceptually different notions of correlation and entanglement [1]. The first one describes correlations between orbitals [2] while the second one refers more to the particle picture [3]. We illustrate those two concepts of orbital and particle correlation and present measures thereof. In particular, we show how they provide a deeper understanding of chemical bonding [4]. Furthermore, we propose a systematic approach to enhancing wave function methods for strongly correlated electron systems, with an emphasis on active space selection [5,6], relevant to both classical and quantum computing. Altogether, these insights highlight the deep connection between quantum information and quantum chemistry.

[1] D.Aliverti-Piuri, K.Chatterjee, L.Ding, K.Liao, J.Liebert, C.Schilling, Faraday Discuss. 254, 76 (2024)

[2] L.Ding, S.Mardazad, S.Das, S.Szalay, U.Schollwöck, Z.Zimborás, C.Schilling, J. Chem. Theory Comput. 17, 79 (2021)

[3] D. Aliverti-Piuri, J. Liebert, C. Schilling, forthcoming

[4] L.Ding, E.Matito, C.Schilling, arXiv:2501.15699, to appear in Nature Commun.

[5] L.Ding, S.Knecht, C.Schilling, J. Phys. Chem. Lett. 14, 11022 (2023)

[6] K.Liao, L.Ding, C.Schilling, J. Phys. Chem. Lett. 15 , 6782 (2024)