Speaker
Description
Arrays of interacting magnetic nanostructures were introduced as a powerful approach to investigate experimentally the exotic many-body physics of frustrated spin models. Following a similar strategy based on lithographically-patterned magnetic lattices, we provide a first attempt to fabricate a lab-on-chip platform to explore the physics of vertex models. The central idea of this work is to replace the spin degree of freedom in artificial frustrated spin systems by a local micromagnetic knob, which can be finely tuned by a proper design of the vertex geometry. This concept is demonstrated both numerically and experimentally on the celebrated six vertex model. Besides, we show how all variants of this model can be apprehended through the engineering of magnetic square lattices. These artificial vertex systems are built from arrays of nanomagnets which are physically connected at the nodes of the lattice. Under such conditions, a non-uniform magnetization distribution appears at the vertices, where the nanomagnets meet. This magnetization distribution shares common features with magnetic domain walls in magnetic nanostrips. By adjusting the vertex geometry, the energy of the different possible ''domain walls'' can be tuned continuously, and the energy hierarchy of the different vertex types can be modified. We then demonstrate that the three predicted phases can be reached experimentally, including the macroscopically degenerate manifold of the disordered phase obtained when all six vertices have the same energy.
