Control of chiral orbital currents in a colossal magnetoresistance material
Control of chiral orbital currents in a colossal magnetoresistance material
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DOI：
10.1038/s41586-022-05262-3
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发表时间：
2022-09
期刊：
影响因子：
64.8
通讯作者：
Yu Zhang;Y. Ni;Hengdi Zhao;Sami Hakani;F. Ye;L. DeLong;I. Kimchi;G. Cao
中科院分区：
文献类型：
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作者：
Yu Zhang;Y. Ni;Hengdi Zhao;Sami Hakani;F. Ye;L. DeLong;I. Kimchi;G. Cao
巨磁电阻效应（CMR）是在磁场存在下电导率的显著增强。它通常与场致自旋极化相关联，场致自旋极化大大降低了自旋散射和电阻。铁磁材料Mn3Si2Te6是一个有趣的例外：它的平面电阻率只有在避免磁极化时才能降低七个数量级。在这里，我们报道了一个奇异的量子态，它是由沿MnTe 6八面体沿着边流动的平面手性轨道电流（COC）驱动的。当外加磁场沿着磁硬轴取向时，逆平面COC的轴轨道矩与亚铁磁Mn自旋耦合，从而显著提高逆平面电导率（CMR）。因此，COC驱动的CMR对超过临界阈值的小直流电流非常敏感，并且可以诱导时间依赖性的、模仿一阶“熔化转变”的开关，该一阶“熔化转变”是COC状态的标志。COC使能CMR的电流控制为量子技术提供了一个新的范例。
Colossal magnetoresistance (CMR) is an extraordinary enhancement of the electrical conductivity in the presence of a magnetic field. It is conventionally associated with a field-induced spin polarization that drastically reduces spin scattering and electric resistance. Ferrimagnetic Mn3Si2Te6is an intriguing exception to this rule: it exhibits a seven-order-of-magnitude reduction inabplane resistivity that occurs only when a magnetic polarization is avoided,. Here, we report an exotic quantum state that is driven byabplane chiral orbital currents (COC) flowing along edges of MnTe6octahedra. Thecaxis orbital moments ofabplane COC couple to the ferrimagnetic Mn spins to drastically increase theabplane conductivity (CMR) when an external magnetic field is aligned along the magnetic hardcaxis. Consequently, COC-driven CMR is highly susceptible to small direct currents exceeding a critical threshold, and can induce a time-dependent, bistable switching that mimics a first-order ‘melting transition’ that is a hallmark of the COC state. The demonstrated current-control of COC-enabled CMR offers a new paradigm for quantum technologies.