主講人： 林倫年主任/研究員 (台灣大學凝態科學研究中心)
題目：What does “quantum materials” mean for chemists like us?
Perhaps many of you may have already heard people whispering about “quantum materials”. It would not be trivial for chemists like us to understand what this term means? However, there have been many review papers explaining this term in physics, chemistry, material science, etc. It seems like a promising land is ahead of us.
One of the quite recent issues of chemical review is a special issue focusing on the quantum materials [1~4], introducing them to chemists. The issue  says “for chemists, … the simplest of definitions is that a quantum material is one whose electronic or magnetic properties are best described as having a nontrivial quantum mechanical origin…. materials where classical particles or calculations that do not take into account the full character of the system do not adequately describe the electronic or magnetic properties displayed.”
It would be interesting to see how “quantum materials” have been interpreted in chemistry so far. To this end, I will briefly review the relationship between molecules (atoms) and crystalline systems by making, in part, a bridge between the physics and chemistry of crystal. Hopefully, I attempt to provide you with some ideas of quantum materials where the interactions of four fundamental degrees of freedom, lattice, charge, orbital, and spin, are dynamically intertwined. For theoretical/computational chemists, you may be curious about how these freedoms are theoretically treated in crystal chemistry [4,5].
 Robert Cava, Nathalie de Leon, Weiwei Xie Chem. Rev. 121, 2777−2779, 2021.
 Nitesh Kumar, Satya N. Guin, Kaustuv Manna, Chandra Shekhar, Claudia Felser, Chem. Rev. 121, 2780-2815, 2021.
 Daniel I. Khomskii and Sergey V. Streltsov, Chem. Rev. 212, 2992-3030, 2021.
 Alex Zunger* and Oleksandr I. Malyi Chem. Rev. 212, 3031-3060 2021.
 Alexander J. Browne, Aleksandra Krajewska Alexandra S. Gibbs, J. Mater. Chem. C 9, 11640-11654, 2021.