Level crossing in the two-dimensional electron system in the presence of gigantic Zeeman effect and quantum Hall ferromagnet

存在巨大塞曼效应和量子霍尔铁磁体的二维电子系统中的能级交叉

• 批准号: 16540280
• 负责人: KURODA Shinji
• 金额: $ 2.24万
• 依托单位: University of Tsukuba
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2004
• 资助国家: 日本
• 起止时间: 2004 至 2006
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-16540280/
• 关键词: Diluted magnetic semiconductors; Two-dimensional electron gas; Quantum Hall effect; Giganric Zeeman splitting; Magneto-transport; Magneto-luminescence; Ferromagnetism; 磁性半導体; 水素クリーニング; 電子移動度; 分子線エピタキシー

The main purpose of this research project is clarifying the physical properties peculiar to the "magnetic" two-dimensional electrons gas (2DEG) originating from the exchange interaction between the 2D electrons and the localized moments of magnetic ions. We have grown modulation-doped heterostructures consisting of the well layer of diluted magnetic semiconductor Cd_<1-x>Mn_xTe and the barrier layer of Cd_<1-y>Mg_yTe by molecular beam epitaxy (MBE) and have investigated the magneto-transport and magneto-optical properties. In order to obtain high-mobility "magnetic" 2DEG, we have first tried several inventions in the MBE growth of non-magnetic heterostructures of CdTe/Cd_<1-y>Mg_yTe. As a result, it was confirmed that the cleaning the surface of a GaAs (001) substrate using hydrogen plasma is effective for removing the oxidized surface layer. By adopting this hydrogen cleaning method also in the growth of Cd_<1-x>Mn_xTe/Cd_<1-y>Mg_yTe, we have succeeded in fabricating high-mobility mag … More netic 2DEG. In the magneto-transport and magneto-optical measurements under high magnetic fields, we have found anomalous behaviors peculiar to magnetic 2DEG, such as an abrupt jump in the magnetic field dependence of energy of the excitonic luminescence at a magnetic field of an integer filling factor. In addition, we have achieved a continuous control of the 2D electron density in the field-effect transistor structure with a gate electrode on the top of the magnetic 2DEG sample fabricated by the photolithography and we etching. In the magneto-transport and magneto-optical measurements under the continuous change of the 2D electron density by applying a gate voltage, we have found anomalous behaviors in the magnetic field dependence of magnetoesistivity, Hall resistivity, and the luminescence energy, which cannot be explained by ordinary integer quantum Hall effect. We have analyzed that these anomalous behaviors are due to the effect of quantum Hall ferromagnet, which originates from the crossing between Landau levels with different spin orientations. Less

该研究项目的主要目的是澄清“磁性”二维电子气（2DEG）所特有的物理性质，该二维电子气（2DEG）源于2D电子与磁性离子的局域化矩之间的交换相互作用。用分子束外延（MBE）方法生长了由稀磁半导体Cd_<1-x>Mn_xTe阱层和Cd_<1-y>Mg_yTe势垒层组成的调制掺杂异质结构，并研究了其磁输运和磁光性质。为了获得高迁移率的“磁性”二维电子气，我们首先在CdTe/Cd_ Mg_yTe非磁性异质结构的MBE生长中尝试了几种发明<1-y>。结果，证实了使用氢等离子体清洁GaAs（001）衬底的表面对于去除氧化的表面层是有效的。在Cd_ Mn_xTe/Cd_ Mg_yTe晶体的生长中也采用了这种氢清洗方法<1-x><1-y>，成功地制备出了高迁移率的磁控管。 ...更多信息 纯二维电子气在高磁场下的磁输运和磁光测量中，我们发现了磁性2DEG特有的异常行为，例如在整数填充因子的磁场下激子发光的能量的磁场依赖性的突然跳跃。此外，我们已经实现了连续控制的场效应晶体管结构的2D电子密度与栅极上的磁性2DEG样品的顶部制造的光刻和我们蚀刻。在二维电子密度连续变化的情况下，通过对样品的磁输运和磁光测量，发现了磁电阻率、霍耳电阻率和发光能量随磁场变化的反常行为，这是普通整数量子霍耳效应所不能解释的.我们分析了这些反常行为是由于量子霍尔铁磁效应引起的，这种效应源于不同自旋取向的朗道能级之间的交叉。少

项目成果

MBE growth an magnetic properties of Cr-doped CdTe(in Japanese)

MBE 生长及 Cr 掺杂 CdTe 的磁性能（日文）

• 发表时间: 2006
• 作者: H. Kinjo;et. al.
• 通讯作者: et. al.

Trion motion in modulation-doped magnetic semiconductor quantm well : Control and observation

调制掺杂磁性半导体量子阱中的三重子运动：控制和观察

• 发表时间: 2006
• 期刊: Physica E 34
• 作者: F. Takano;et. al.
• 通讯作者: et. al.

X-ray absorption near-edge structure and valence state of Mn in (Ga,Mn)N

• DOI: 10.1103/physrevb.72.115209
• 发表时间: 2005-09
• 期刊: Physical Review B
• 影响因子: 3.7
• 作者: A. Titov;X. Biquard;D. Halley;S. Kuroda;E. Bellet-Amalric;H. Mariette;J. Cibert;A. Merad;G. Merad;M. Kanoun;E. Kulatov;Y. Uspenskiǐ

Suppression of ferromagnetism due to hole doping in Zn_<1-x>Cr_xTe grown by molecular beam epitaxy

分子束外延生长Zn_<1-x>Cr_xTe中空穴掺杂对铁磁性的抑制

• 发表时间: 2005
• 期刊: Appl.Phys.Lett 87
• 作者: N.Ozaki;I.Okabayashi;T.Kumekawa;N.Nishizawa;S.Marcet;S.Kuroda;K.Takita
• 通讯作者: K.Takita

Fabrication and characterization of n-type modulation-doped(Cd, Cr)Te quantum well

n型调制掺杂(Cd,Cr)Te量子阱的制备与表征

• 发表时间: 2007
• 期刊: AIP Conference Proceedings 893
• 作者: F.Takano;T. Nishizawa;H.Kijo;J. W. Lee;S. Kuroda;H. Ofuchi;Y. Imanaka;T. Takamasu;G. Kido;K. Takita;H. Akinaga
• 通讯作者: H. Akinaga