Field-Induced Magnetic Monopole Plasma in Artificial Spin Ice
Field-Induced Magnetic Monopole Plasma in Artificial Spin Ice
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DOI：
10.1103/physrevx.11.011042
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发表时间：
2021-03-02
影响因子：
12.5
通讯作者：
Crooker, S. A.
中科院分区：
文献类型：
--
作者：
Goryca, M.;Zhang, X.;Crooker, S. A.
人工自旋冰（ASIs）是光刻定义的纳米磁体的相互作用阵列，其中可以有意地设计新颖的受抑磁相。一个关键的新兴描述的基本激发在ASI是磁粒子-移动准粒子，携带有效的磁荷。在这里，我们证明了原型方形ASI晶格可以主机，在其磁相图的特定区域，含有高密度的移动的磁单极等离子体制度。这些区域是由连接移动的单极子的狄拉克弦上的磁场可调张力造成的。通过被动地“听”自发的热噪声的条件下，严格的热平衡，我们揭示了它们的内在动力学和热动力学是最扩散（即，最低限度地相关）在等离子体制度。这些结果为具有连续场可调密度和动态特性的按需磁制度打开了大门，从而为探测合成物质中有效磁荷的物理学提供了新的范例。
Artificial spin ices (ASIs) are interacting arrays of lithographically defined nanomagnets in which novel, frustrated magnetic phases can be intentionally designed. A key emergent description of fundamental excitations in ASIs is that of magnetic monopoles-mobile quasiparticles that carry an effective magnetic charge. Here, we demonstrate that the archetypal square ASI lattice can host, in specific regions of its magnetic phase diagram, plasmalike regimes containing a high density of mobile magnetic monopoles. These regimes result from the magnetic field-tunable tension on the Dirac strings connecting mobile monopoles. By passively "listening" to spontaneous monopole noise under conditions of strict thermal equilibrium, we reveal their intrinsic dynamics and show that monopole kinetics are most diffusive (that is, minimally correlated) in the plasma regime. These results open the door to on-demand monopole regimes having continuously field-tunable densities and dynamic properties, thereby providing a new paradigm for probing the physics of effective magnetic charges in synthetic matter.