复合费米子的Bloch铁磁性
Bloch Ferromagnetism of Composite Fermions
摘要：
1929年，费利克斯·布洛赫提出，顺磁性费米电子海应该在非常低的密度下自发跃迁到完全磁化状态，因为通过排列自旋获得的交换能超过了动能的增加。我们在这里报告观察到一个突然的，相互作用驱动的过渡到完全磁化，高度让人想起布洛赫铁磁性，在过去的90年里一直逃避实验。我们的平台是奇异的二维费米海的复合费米子在半填充的最低朗道水平。通过对费米波矢的定量测量，我们观察到当我们降低复合费米子的密度时，从部分自旋极化到完全自旋极化的基态的突然转变。我们详细的理论计算提供了这种现象的半定量的帐户。
英文摘要：
In 1929 Felix Bloch suggested that the paramagnetic Fermi sea of electrons should make a spontaneous transition to a fully-magnetized state at very low densities, because the exchange energy gained by aligning the spins exceeds the enhancement in the kinetic energy. We report here the observation of an abrupt, interaction-driven transition to full magnetization, highly reminiscent of Bloch ferromagnetism that has eluded experiments for the last ninety years. Our platform is the exotic two-dimensional Fermi sea of composite fermions at half-filling of the lowest Landau level. Via quantitative measurements of the Fermi wavevector, which provides a direct measure of the spin polarization, we observe a sudden transition from a partially-spin-polarized to a fully-spin-polarized ground state as we lower the composite fermions' density. Our detailed theoretical calculations provide a semi-quantitative account of this phenomenon.
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。
