Institut für Laserphysik, Universität Hamburg, D-22761 Hamburg, Germany.
Science. 2011 Aug 19;333(6045):996-9. doi: 10.1126/science.1207239. Epub 2011 Jul 21.
Magnetism plays a key role in modern technology and stimulates research in several branches of condensed matter physics. Although the theory of classical magnetism is well developed, the demonstration of a widely tunable experimental system has remained an elusive goal. Here, we present the realization of a large-scale simulator for classical magnetism on a triangular lattice by exploiting the particular properties of a quantum system. We use the motional degrees of freedom of atoms trapped in an optical lattice to simulate a large variety of magnetic phases: ferromagnetic, antiferromagnetic, and even frustrated spin configurations. A rich phase diagram is revealed with different types of phase transitions. Our results provide a route to study highly debated phases like spin-liquids as well as the dynamics of quantum phase transitions.
磁性在现代技术中起着关键作用，并激发了凝聚态物理多个分支的研究。尽管经典磁性理论已经相当完善，但广泛可调谐实验系统的演示仍然是一个难以实现的目标。在这里，我们通过利用量子系统的特殊性质，在三角晶格上实现了经典磁性的大规模模拟器。我们利用被困在光学晶格中的原子的运动自由度来模拟各种磁性相：铁磁、反铁磁，甚至是受挫的自旋构型。揭示了具有不同类型相变的丰富相图。我们的结果为研究像自旋液体这样备受争议的相以及量子相变的动力学提供了一种途径。
