Spin Supersolid State and Quantum Phase Transition Cooling in a Triangular Lattice Antiferromagnet

Abstract:

Prototypical models and their material incarnations are cornerstones to the understanding of quantum magnetism. Here we show theoretically that the recently synthesized magnetic compound Na2BaCo(PO4)2 (NBCP) is a rare, nearly ideal material realization of the S=1/2 triangular lattice antiferromagnet with significant easy-axis anisotropy. According to the established model, the NBCP hosts a spin supersolid state that breaks both the lattice translation and the spin rotational symmetries, a magnetic analogue of the long-sought supersolid quantum state. Near the quantum phase transition and also persistently in the supersolid phase, we observe prominent magnetic cooling effect till very low temperatures. The compound NBCP therefore represents an ideal platform to explore the physics of spin supersolidity and serves as a promising quantum magnet coolant.

Bio:

李伟，中科院理论物理研究所研究员，研究方向为强关联多体理论与计算、量子磁性与关联电子系统前沿问题，在国际学术期刊发表论文近70篇，包括PRL/PRX/Nature Commun.12篇，获国家基金委优青资助，中科院-财政部基础研究领域稳定支持青年团队负责人。