Department of Quantum Matter Physics, University of Geneva, 24 Quai Ernest Ansermet, CH-1211, Geneva, Switzerland.
Group of Applied Physics, University of Geneva, 24 Quai Ernest Ansermet, CH-1211, Geneva, Switzerland.
Nat Commun. 2018 Jun 28;9(1):2516. doi: 10.1038/s41467-018-04953-8.
Magnetic layered van der Waals crystals are an emerging class of materials giving access to new physical phenomena, as illustrated by the recent observation of 2D ferromagnetism in CrGeTe and CrI. Of particular interest in semiconductors is the interplay between magnetism and transport, which has remained unexplored. Here we report magneto-transport measurements on exfoliated CrI crystals. We find that tunneling conduction in the direction perpendicular to the crystalline planes exhibits a magnetoresistance as large as 10,000%. The evolution of the magnetoresistance with magnetic field and temperature reveals that the phenomenon originates from multiple transitions to different magnetic states, whose possible microscopic nature is discussed on the basis of all existing experimental observations. This observed dependence of the conductance of a tunnel barrier on its magnetic state is a phenomenon that demonstrates the presence of a strong coupling between transport and magnetism in magnetic van der Waals semiconductors.
磁性层状范德华晶体是一类新兴的材料，它们可以展现出许多新的物理现象，例如最近在 CrGeTe 和 CrI 中观察到的二维铁磁性。在半导体中，特别有趣的是磁学和输运之间的相互作用，而这方面仍未得到探索。在这里，我们报告了在剥离的 CrI 晶体上的磁输运测量结果。我们发现，垂直于晶体平面的隧道传导表现出高达 10000%的磁电阻。磁电阻随磁场和温度的演化表明，这种现象源于多个向不同磁态的跃迁，而其可能的微观性质则基于所有现有实验观测进行了讨论。这种隧道势垒的电导对其磁态的依赖性表明，在磁性范德华半导体中，输运和磁学之间存在很强的耦合。
