LaBi和LaSb中奇异电子表面态的存在
Presence of Exotic Electronic Surface States in LaBi and LaSb
摘要：
镧系金属氧化物La $X$（$X$ = Sb，Bi）具有极高的磁电阻效应，近年来引起了人们的广泛兴趣。然而，它们完美的电子空穴补偿提供了另一种解释，因此拓扑表面态的可能作用需要通过直接观察来验证。我们的角分辨光电子能谱（ARPES）数据显示，在两种材料的费米能级附近的多个Dirac-like表面状态。有趣的是，我们已经观察到圆二色性在表面和近表面的散装带。因此，自旋-轨道耦合诱导的轨道和自旋角动量织构可能提供了一种机制，禁止在零场的背散射，表明表面和近表面的体带可能有助于强烈的XMR在La $X$。这些材料极其简单的岩盐结构和高质量晶体的容易制备表明，它们可能是进一步研究拓扑物质的理想平台。
英文摘要：
Extremely high magnetoresistance (XMR) in the lanthanum monopnictides La$X$ ($X$ = Sb, Bi) has recently attracted interest in these compounds as candidate topological materials. However, their perfect electron-hole compensation provides an alternative explanation, so the possible role of topological surface states requires verification through direct observation. Our angle-resolved photoemission spectroscopy (ARPES) data reveal multiple Dirac-like surface states near the Fermi level in both materials. Intriguingly, we have observed circular dichroism in both surface and near-surface bulk bands. Thus the spin-orbit coupling-induced orbital and spin angular momentum textures may provide a mechanism to forbid backscattering in zero field, suggesting that surface and near-surface bulk bands may contribute strongly to XMR in La$X$. The extremely simple rock salt structure of these materials and the ease with which high-quality crystals can be prepared suggests that they may be an ideal platform for further investigation of topological matter.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
