用磁力显微镜研究Cu $_2$ OSeO $_3$中磁场诱导的螺旋有序重取向
Field-induced reorientation of helimagnetic order in Cu$_2$OSeO$_3$ probed by magnetic force microscopy
摘要：
Cu $_2$ OSeO $_3$是具有磁电耦合的绝缘skyrmion-主体材料，该磁电耦合引起具有对磁场$\vec H$的特征依赖性的电极化的强度。我们报告了磁力显微镜成像的螺旋实空间自旋结构的表面上的大块单晶Cu $_2$ OSeO $_3$。在磁场的存在下，helmagnetic顺序一般重定向，并获得均匀的磁化分量，导致在较大的领域的圆锥形排列。我们研究了在10 K的温度下，接近晶体学$\langle 110\rangle$方向的场的重取向过程，该方向涉及$H_{c1}$的相变。实验证据的磁畴在真实空间中的形成，以及伴随着重新取向过程的弛豫事件的微观起源。此外，电极化的强度是通过开尔文探针力显微镜测量。我们表明，电极化的强度的特征场依赖性起源于这种螺旋磁重取向过程。我们的实验结果很好地描述了一个有效的朗道理论先前调用MnSi，捕获磁晶各向异性和塞曼能量之间的竞争。
英文摘要：
Cu$_2$OSeO$_3$ is an insulating skyrmion-host material with a magnetoelectric coupling giving rise to an electric polarization with a characteristic dependence on the magnetic field $\vec H$. We report magnetic force microscopy imaging of the helical real-space spin structure on the surface of a bulk single crystal of Cu$_2$OSeO$_3$. In the presence of a magnetic field, the helimagnetic order in general reorients and acquires a homogeneous component of the magnetization, resulting in a conical arrangement at larger fields. We investigate this reorientation process at a temperature of 10~K for fields close to the crystallographic $\langle 110\rangle$ direction that involves a phase transition at $H_{c1}$. Experimental evidence is presented for the formation of magnetic domains in real space as well as for the microscopic origin of relaxation events that accompany the reorientation process. In addition, the electric polarization is measured by means of Kelvin-probe force microscopy. We show that the characteristic field dependency of the electric polarization originates in this helimagnetic reorientation process. Our experimental results are well described by an effective Landau theory previously invoked for MnSi, that captures the competition between magnetocrystalline anisotropies and Zeeman energy.
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。
