연사: Danh Xuan Ngo from UC Berkeley

일시: 2026년 9월 30일 2:00 – 3:00pm

장소: 연구협력관 B1 Jupiter 세미나룸

세미나 명: "Synthetic Mastery Over Spin Hamiltonian Terms in Molecular Magnets and Qubits"

초록: Insight into rationally maximizing or minimizing spin Hamiltonian properties is paramount in shaping the landscape of quantum magnetism, from molecular magnets and qubits to single-atom magnets and beyond.

This talk will cover four spin-Hamiltonian-first approaches in the synthesis of single-molecule magnets and qubits: (i) the Zeeman interaction is isolated via synthesis of the mellitic trianhydride anion $[C_{12}O_{9}]^{1-}$ a nuclear-spin-free radical that exhibits record coherence times $T_{2}$ at cryogenic temperatures; (ii) a massive hyperfine coupling $A_{Iso}(^{175}\text{Lu}) = 4.38\text{ GHz}$ is achieved via a high-symmetry crystal field at $\text{Lu}^{2+}$ which maximizes 6s 5de mixing; (iii) a large and ferromagnetic exchange coupling $J_{ex} = 55.6(6)\text{ cm}^{-1}$ is achieved in radical-bridged dilanthanide complexes via a planar benzene trianion radical and lastly, (iv) a staggering zero-field splitting $D = 7600\text{ cm}^{-1}$ (0.94 eV) is achieved in an adatom-like Bi(0) complex via monocoordination and retention of orbital angular momentum. 

The spin Hamiltonian engineering lessons learned via the precise atomic placement afforded by chemical synthesis may serve to guide the design of next-generation single-atom magnets and qubits with increased thermal stability and magnetic bistability.