Macrocoherence in bilayer quantum Hall state

双层量子霍尔态的宏观相干性

• 批准号: 11304019
• 负责人: SAWADA Anju
• 金额: $ 22.27万
• 依托单位: Tohoku University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (A)
• 财政年份: 1999
• 资助国家: 日本
• 起止时间: 1999 至 2001
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-11304019/
• 关键词: Quantum Hall effect; Composite Boson; Activation energy; Interlayer coherence; Bose condensation; Gallium Arsenide; Pseudospin; Spin; 擬スピン; ホールプラトー; スカーミオン

Skyrmion excitations were measured and compared for the first time in the bilayer quantum Hall (QH) state at the Landau-level filling factor ν=2 and in the monolayer QH state at ν=1. The observed number of flipped spins, Ns, is 14 in the bilayer sample with a large tunneling gap, and Ns=7 in the bilayer sample with a small tunneling gap, while it is Ns=7 in the monolayer sample. The difference is interpreted to be due to the interlayer exchange interaction.In the next stage, we measured the magnetoresistance of bilayer QH effects at the fractional filling factor ν=2/3 by changing the total electron density and the density difference between two layers. Three different QH states were separated by two types of phase transition : One is the spin transition and the other is the pseudospin transition. In addition, two different hystereses were detected, one of which is specific to bilayer systems. The phase transitions and the hystereses are described well by a composite fermion model extended to a bilayer system.

测量了Skyrmion兴奋，并在Landau级填充因子ν= 2的双层量子厅（QH）状态下首次进行了比较。在双层样品中，观察到的翻转旋转数量为14个，具有较大的隧穿缝隙，在双层样品中ns = 7的ns = 7，带有较小的隧穿间隙，而单层样品中的ns = 7。差异被解释为是由于层间交换的相互作用。在下一阶段，我们通过更改两个层之间的总电子密度和密度差来测量分数填充因子ν= 2/3处双层QH效应的磁性。通过两种类型的相转换将三种不同的QH状态分开：一种是自旋跃迁，另一个是伪旋转过渡。此外，检测到了两个不同的秘诀，其中一个特定于双层系统。相变和扰动是通过扩展到双​​层系统的复合费米模型很好地描述的。

项目成果

A.Sawada: "Bilayer v=2 Quantum Hall State in Parallel High Magnetic Field"Physica E. 6・1-4. 615-618 (2000)

A.Sawada：“平行强磁场中的双层 v=2 量子霍尔态”Physica E. 6・1-4 (2000)。

Z.F.Ezawa: "Interlayer exchange interactions, SU(4) soft waves, and skyrmions in bilayer quantum Hall ferromagnets"Physical Review B. 65. 75311-75321 (2002)

Z.F.Ezawa：“双层量子霍尔铁磁体中的层间交换相互作用、SU(4) 软波和斯格明子”物理评论 B. 65. 75311-75321 (2002)

Z.F.Ezawa: "Skyrmions and quantum Hall ferromagnets in improved composite-boson theory"J. Phys. Soc. Jpn.. 68. 576-585 (1999)

Z.F.Ezawa：“改进的复合玻色子理论中的斯格明子和量子霍尔铁磁体”J。

M.Kasaya: "Crystal electric field and quadrupole ordering in semiconducting PrPtBi"Phsica B. 281&282. 579-580 (2000)

M.Kasaya：“半导体 PrPtBi 中的晶体电场和四极排序”Phsica B.281

Z.F.Ezawa: "Spin-Pseudospin Coherence and CP^3 Skyrmions in Bilayer Quantum Hall Ferromagnets"Physical Review Letters. 82・26. 3512-3515 (1999)

Z.F.Ezawa：“双层量子霍尔铁磁体中的自旋-赝自旋相干性和 CP^3 斯格明子”物理评论快报 82・26（1999）。