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Updated: May 9, 2026

Measurement of Ultrafast Vibrational Coherences in Polyatomic Radical Cations with Strong-Field Adiabatic Ionization
Published on: August 6, 2018
Quantum Phase Transition of a Molecular Radical Pair
Xin Li1, Tie-Feng Fang2, Yang He3
1Center for Carbon-Based Electronics and Key Laboratory for the Physics and Chemistry of Nanodevices, School of Electronics, Peking University, Beijing 100871, China.
Abstract:
Quantum phase transitions lie at the heart of condensed matter physics. Observing these transitions, however, requires the careful engineering of materials to realize specific, finely tuned systems. In this work, we demonstrate a quantum phase transition within artificial molecular spin pairs, where the ground state can be controllably switched between the antiferromagnetic phase and ferromagnetic phase by an external magnetic field. The combination of scanning tunneling microscopy experiments and theoretical calculations not only reveals the microscopic details of this phase transition but also establishes that its critical behavior is tunable through precise modulation of the intermolecular interactions. These results establish a practical platform for exploring quantum phase transitions in molecular systems.
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