论文标题
在兰道级交叉处的量子大厅铁磁铁的自旋逆转
Spin Reversal of a Quantum Hall Ferromagnet at a Landau Level Crossing
论文作者
论文摘要
当Landau水平（LLS）在量子大厅方面的费米能量附近退化时，相互作用效应会大大改变电子基态。我们研究了在ll填充因子周围$ν= 1 $的量子大厅的量子霍尔·铁磁体在ll填充因子$ν= 1 $周围形成。强耦合方案中的空腔光谱使我们能够光学地提取二维孔气体的自旋极化。通过分析这种极化是孔密度和磁场的函数，我们观察到铁磁铁的自旋翻转。此外，去极化远离$ν= 1 $靠近LL交叉口的加速度。这表明随着LL交叉处的有效Zeeman能量消失，Skyrmion激发的大小增加。
When Landau levels (LLs) become degenerate near the Fermi energy in the quantum Hall regime, interaction effects can drastically modify the electronic ground state. We study the quantum Hall ferromagnet formed in a two-dimensional hole gas around the LL filling factor $ν=1$ in the vicinity of a LL crossing in the heave-hole valence band. Cavity spectroscopy in the strong-coupling regime allows us to optically extract the two-dimensional hole gas' spin polarization. By analyzing this polarization as a function of hole density and magnetic field, we observe a spin flip of the ferromagnet. Furthermore, the depolarization away from $ν=1$ accelerates close to the LL crossing. This is indicative of an increase in the size of Skyrmion excitations as the effective Zeeman energy vanishes at the LL crossing.
