我们报告的测量自旋磁化率和电子有效质量的二维电子限制在界面的MgxZn 1-xO/ZnO单异质结构(x = 0.05,0.08,和0.11),生长在(0001)ZnO衬底上的分子束外延。通过控制势垒成分来调节内置极化,电子密度在5.6 x 10^11 ~ 1.6 x 10^12 cm^-2范围内系统地变化,对应的范围为3.1 < rs < 5.2,其中rs是以有效玻尔半径为单位测量的平均电子间距。我们使用符合技术,自旋分裂朗道能级的交叉发生在磁场的临界倾斜角,以评估自旋磁化率。此外,我们确定了有效质量的温度依赖性的Shubnikov-de Haas振荡测量符合条件。磁化率和有效质量都随着电子密度的减小而逐渐增大,反映了电子-电子相互作用的作用。
英文摘要:
We report measurements of the spin susceptibility and the electron effective mass for two-dimensional electrons confined at the interfaces of MgxZn1-xO/ZnO single heterostructures (x = 0.05, 0.08, and 0.11), grown by molecular-beam epitaxy on (0001) ZnO substrates. By tuning the built-in polarization through control of the barrier composition, the electron density was systematically varied in the range of 5.6 x 10^11 to 1.6 x 10^12 cm^-2, corresponding to a range of 3.1 < rs < 5.2, where rs is the average electron spacing measured in units of the effective Bohr radius. We used the coincidence technique, where crossings of the spin-split Landau levels occur at critical tilt angles of magnetic field, to evaluate the spin susceptibility. In addition, we determined the effective mass from the temperature dependence of the Shubnikov-de Haas oscillations measured at the coincidence conditions. The susceptibility and the effective mass both gradually increase with decreasing electron density, reflecting the role of electron-electron interaction.
Tunable electronic properties and band alignments of MoSi$_2$N$_4$/GaN and MoSi$_2$N$_4$/ZnO van der Waals heterostructures
范德华异质结构(VDWH)是一种新兴的策略,工程的二维(2D)材料系统的电子性能。最近发现的MoSi $_2$ N $_4$-一个合成的七层的二维半导体具有特殊的机械和电子性能的启发,我们调查的协同作用\ce{MoSi2N4}与宽带隙(WBG)的GaN和ZnO的二维单层使用第一性原理计算。发现MoSi $_2$ N $_4$/GaN是直接带隙的I型VDHH,而MoSi $_2$ N $_4$/ZnO是间接带隙的II型VDHH.有趣的是,通过沿面外方向施加电场或机械应变,MoSi $_2$ N $_4$/GaN和MoSi $_2$ N $_4$/ZnO的能带结构可以被显著地改变,表现出丰富的过渡行为,例如I型到II型能带对准和直接到间接带隙转变。这些发现揭示了MoSi $_2$ N $_4$基WBG VDWH作为超紧凑光电应用中具有巨大设计灵活性的可调谐混合材料的潜力。
Band Gap Opening and Optical Absorption Enhancement in Graphene using ZnO Nanoclusters
采用第一性原理密度泛函理论研究了石墨烯/ZnO异质结构的电子、光学和输运性质。结果表明,Zn 12 O 12在石墨烯中的禁带宽度为14.5meV,在可见光至红外波段的吸收率提高了1.67倍,并表现出轻微的非线性I-V特性。这些发现设想石墨烯/Zn 12 O 12异质结构可以适用于能量收集、光电探测和光化学器件。
ZnO/ZnS heterostructures as hole reservoir to boost Ni foam energy storage performance
University of Catania(卡塔尼亚大学);IMM-CNR(意大利国家研究委员会材料研究所);Catalan Institute of Nanoscience and Nanotechnology (ICN2)(加泰罗尼亚纳米科学和技术研究所);CSIC(西班牙国家研究委员会);BIST(巴塞罗那科学技术研究院);ICREA(加泰罗尼亚卓越研究员)
High frequency susceptibility of a weak ferromagnet with magnetostrictive magnetoelectric coupling: using heterostructures to tailor electromagnon frequencies
Enhanced interfacial charge transfer by Z-scheme in defect-mediated ZnO-CdS nano-composite with rGO as a solid-state electron mediator for efficient photocatalytic applications
Resistive switching in HfO2-x/La0.67Sr0.33MnO3 heterostructure: An intriguing case of low H-field susceptibility of an E-field controlled active interface
Systematic Study of Amorphous ABC Heterostructures at the Atomic Scale as a Second-Order Nonlinear Optical Metamaterial
Friedrich Schiller University Jena(耶拿弗里德里希·席勒大学);Australian National University(澳大利亚国立大学);Fraunhofer Institute for Applied Optics and Precision Engineering IOF(弗劳恩霍夫应用光学和精密工程研究所);GFZ Helmholtz Centre for Geosciences(德国地球科学研究中心赫尔姆霍茨协会);Fraunhofer Institute for Microstructure of Materials and Systems IMWS(弗劳恩霍夫材料系统和微结构研究所)
Polarization discontinuity driven two dimensional electron gas at A$_2$Mo$_3$O$_8$/B$_2$Mo$_3$O$_8$ (A, B : Zn,Mg,Cd) interfaces
我们提出了一种新的异质结构系统,由具有化学式A $_2$ Mo $_3$ O $_8$(A,B:Zn,Mg,Cd)的化合物组成,可以容纳二维电子/空穴气(2DEG/2DHG)。我们利用第一性原理方法和Berry相方法研究了这些化合物的自发极化和压电性质。我们表明,这种异质结构是非常稳定的,由于极低的界面应变。在Zn $_2$ Mo $_3$ O $_8$ /Mg $_2$ Mo $_3$ O $_8$的情况下研究了2DEG/2DHG的形成,并且已经发现极化不连续是驱动机制。已经发现在这些异质结构中的片状载流子密度和电荷局部化在通过类似机制承载2DEG的其他公知系统(例如AlN/Al(Ga)N或ZnO/Zn(Mg)O)中具有相同的数量级。除了2DEG的常规应用之外,这些材料还有望成为令人兴奋的开创性技术,例如使用太阳辐射的压电光电子学,因为由于$\sim$ 2 eV的低光学带隙,它们还能够吸收太阳辐射的很大一部分
Physics-Informed Long-Range Coulomb Correction for Machine-learning Hamiltonians
Key Laboratory of Computational Physical Sciences (Ministry of Education)(计算物理科学国家重点实验室(教育部));Institute of Computational Physical Sciences(计算物理科学研究院);State Key Laboratory of Surface Physics(表面物理国家重点实验室);Department of Physics, Fudan University, Shanghai, 200433, China.(复旦大学物理系,上海,200433,中国)
Two-dimensional helical superconductivity and gapless superconducting edge modes in the 1T$^\prime$-WS$_2$/2H-WS$_2$ heterophase bilayer
University of California, Santa Barbara(加州大学圣塔芭芭拉分校);Brookhaven National Laboratory(布鲁海文国家实验室);Stony Brook University(石溪大学);Flatiron Institute(平顿研究所);University of Wisconsin-Madison(威斯康星大学麦迪逊分校);University of Nevada, Reno(内华达大学里诺分校)
Symmetry-Based Design Rules for Second-Harmonic Generation in Stacked and Twisted MoS2 Bilayers
Institute of Condensed Matter Theory and Optics, Friedrich Schiller University Jena(耶拿弗里德里希·席勒大学凝聚态理论与光学研究所);Abbe Center of Photonics, Friedrich-Schiller-Universität Jena(耶拿弗里德里希·席勒大学阿贝光子学中心)