Rivlis Raz, Zadorozhnyi Andrei, Dahnovsky Yuri
Department of Physics and Astronomy/3905, University of Wyoming, 1000 E. University Avenue, Laramie, WY 82071, United States of America.
Department of Physics, Georgetown University, 37th Street, Washington, DC 20057, United States of America.
J Phys Condens Matter. 2024 Oct 14;37(1). doi: 10.1088/1361-648X/ad80f1.
We study magnetotransport in conical helimagnet crystals using the nonequilibriun Boltzmann equation approach. Spin dependent magnetoresistance exhibits dramatic properties for high and low electron concentrations at different temperatures. For spin up electrons we find negative magnetoresistance despite only considering a single carrier type. For spin down electrons we observe giant magnetoresistance due to depletion of spin down electrons with an applied magnetic field. For spin up carriers, the magnetoresistance is negative, due to the increase in charge carriers with a magnetic field. In addition, we investigate the spin dependent Hall effect. If a magnetic field reaches some critical value for spin down electrons, giant Hall resistance occurs, i.e. Hall current vanishes. This effect is explained by the absence of spin down carriers. For spin up carriers, the Hall constant dramatically decreases with field, due to the increase in spin up electron density. Because of the giant spin dependent magnetoresistance and Hall resistivity, conical helimagnets could be useful in spin switching devices.
我们使用非平衡玻尔兹曼方程方法研究锥形螺旋磁体晶体中的磁输运。自旋相关的磁电阻在不同温度下对高电子浓度和低电子浓度表现出显著特性。对于自旋向上的电子，尽管仅考虑单一载流子类型，我们仍发现了负磁电阻。对于自旋向下的电子，由于施加磁场导致自旋向下电子的耗尽，我们观察到了巨磁电阻。对于自旋向上的载流子，由于磁场使电荷载流子增加，磁电阻为负。此外，我们研究了自旋相关的霍尔效应。当磁场达到自旋向下电子的某个临界值时，会出现巨霍尔电阻，即霍尔电流消失。这种效应可通过自旋向下载流子的缺失来解释。对于自旋向上的载流子，由于自旋向上电子密度的增加，霍尔常数随磁场急剧下降。由于巨大的自旋相关磁电阻和霍尔电阻率，锥形螺旋磁体在自旋开关器件中可能会有用。
