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1.
张栩  孟子杨  黄美珍  王宁 《物理》2023,(9):642-644
<正>量子霍尔效应(quantum Hall effect, QHE)是霍尔效应的量子力学版本。一般分为整数量子霍尔效应(integer QHE)和分数量子霍尔效应(fraction QHE),其中整数量子霍尔效应由德国物理学家von Klitzing发现,他因此获得1985年诺贝尔物理学奖。分数量子霍尔效应由美籍华裔物理学家崔琦、德国物理学家Horst St?rmer和美国材料学家Arthur Gossard发现,前两位因此与美国物理学家Robert Laughlin分享了1998年诺贝尔物理学奖。  相似文献   

2.
分数量子霍尔效应——1998年诺贝尔物理学奖介绍   总被引:3,自引:0,他引:3  
郑厚植 《物理》1999,28(3):131-132
1998年10月,三位美国科学院,DanielTsui、HosrstStormer和RobertLaughlin,因他们在发现分数量子霍尔效应方面所作出的杰出贡献而获得诺贝尔物理学奖。文章力图从物理角度概要介绍了分数量子霍尔效应的主要物理现象和机制。  相似文献   

3.
回顾了霍尔效应、量子霍尔效应及量子反常霍尔效应的探索历程.着重叙述了1985年、1998年获得诺贝尔物理学奖的量子霍尔效应研究成果,以及在我国实验室首次观测到量子反常霍尔效应的重大成就.  相似文献   

4.
戴闻 《物理》2003,32(7):470-470
继冯·克利青 (vonKlitzing) 1980年发现整数量子霍尔效应之后 ,美籍华裔科学家崔琦于 1982年发现了分数量子霍尔效应———受限于平面的二维电子气 ,在强外场B垂直于平面的条件下 ,其霍尔电压VH 作为B的函数表现出一连串的平台 ;与每一平台相对应的霍尔电阻VH/I(I是沿平面的纵向电流 )恰好等于物理常数h/e2 除以一个分数ν(ν =2 / 3,3/ 5 ,2 / 5 ,1/ 3… ) .当外场B较低时 ,发生整数量子霍尔效应 ,此时 ,与上述ν相对应的是克里青整数i(i =1,2 ,3… ) ,i的物理意义是每一根量子磁通所分摊到的电子数 .在外场的作用下 ,每一个电子绕其…  相似文献   

5.
戴闻 《物理》2006,35(9):794-794
一块长方形的金属板置于磁场中,磁场的方向(z方向)垂直于板面,在板的纵向(x方向)通入电流,则在板的横向(y方向)可检测到霍尔电压。1879年,Edwin Hall发现了上述正负电荷非平衡聚积的现象,后来被命名为霍尔效应。100年后,1980年和1982年,von Klitzing和崔琦等利用二维电子气作为样品,在高场下分别发现了整数量子霍尔效应和分数量子霍尔效应,并先后获得诺贝尔物理学奖。最近,来自哈佛大学物理系的Tinkham等在Nature剧刊撰文,报告了他们用电学方法在探测自旋霍尔效应的实验中所取得的进展。  相似文献   

6.
分数量子霍尔效应系统是奇异的量子液体,其中的准粒子激发可以带分数电荷,甚至具有非阿贝尔的统计性质。理论研究表明,这些准粒子可以用来实现在硬件上可容错的量子计算,即拓扑量子计算。文章在介绍分数量子霍尔效应及其在拓扑量子计算中的潜在应用基础上,重点回顾了近五年来对填充因子为5/2的分数量子霍尔态中非阿贝尔准粒子的实验探测和部分相关理论诠释。  相似文献   

7.
量子霍尔效应   总被引:7,自引:1,他引:6  
从经典的霍尔效应开始,比较系统地、深入浅出地介绍了量子霍尔效应及其所涉及的一些新概念和实际应用。  相似文献   

8.
文章从平常霍尔效应出发,介绍了反常霍尔效应及其内秉物理机制,并在此基础上介绍了其量子化版本——量子化反常霍尔效应.然后从拓扑有序态的角度,重点讨论了量子化反常霍尔效应与量子霍尔效应、量子自旋霍尔效应、拓扑绝缘体等之间的区别与内在联系.最后介绍了通过在拓扑绝缘体(Bi2Se3,Bi2Te3和Sb2Te3)薄膜中掺杂过渡金属元素(Cr或Fe)实现量子化反常霍尔效应的方法.  相似文献   

9.
戴闻 《物理》2001,30(7):447-449,431
在经典霍尔效应中 ,霍尔电压VH 线性正比于垂直方向的外场B⊥ ,并且沿电流方向的纵向电压V∥ 也随B⊥ 的增加而连续上升 .1980年 ,冯·克里青 (KlausvonKlitzing)用半导体场效应晶体管进行霍尔测量 ,研究被限制在二维平面内的电子运动 .他发现 ,在极低温和强磁场的条件下 ,霍尔电压VH 不再随外场的增加而线性增加 ,而是 (在VH-B⊥ 图上 )表现为一连串VH =常数的阶跃平台 .与一个个平台相对应的霍尔电阻VH I(I是纵向电流 )恰好等于物理常数h e2 除以一个整数i(i=1,2 ,3,4 ,… ) .克里青的发现后来被称为…  相似文献   

10.
研究了Rashba自旋轨道耦合作用下的二维无限长条形样品中的电子输运,计算了样品的霍尔电导和纵向电阻,得到了完整的整数量子霍尔效应.在一定强磁场范围内,由于样品两边缘的限制,能级在大波矢范围快速上升,在小波矢范围形成平坦的朗道能级.强磁场下自旋轨道耦合完全解除自旋简并.位于朗道能级上升和下降区域的电子形成传输电流.计算结果表明,霍尔电导呈现台阶型,平台出现在e2/h的整数倍位置,形成霍尔平台.温度对霍尔平台的电导有一定影响.在某临界温度以下,霍尔平台电导可以达到10–9以上的精度.最后分析了声子发射和吸收产生整数量子霍尔效应的纵向电阻的机制,近似计算了弛豫时间,得到了纵向电阻.结果表明,纵向电阻在霍尔平台区域为零,而在霍尔平台之间出现峰值.  相似文献   

11.
A simple route to generate magnetotransport data is reported that results in fractional quantum Hall plateaus in the conductance without invoking strongly correlated physics. Ingredients to the generating model are conducting tiles with integer quantum Hall effect and metallic linkers, further Kirchhoff rules. When connecting few identical tiles in a mosaic, fractional steps occur in the conductance values. Richer spectra representing several fractions occur when the tiles are parametrically varied. Parts of the simulation data are supported with purposefully designed graphene mosaics in high magnetic fields. The findings emphasize that the occurrence of fractional conductance values, in particular in two‐terminal measurements, does not necessarily indicate interaction‐driven physics. The importance of an independent determination of charge densities is underscored and similarities with and differences to the fractional quantum Hall effect are critically discussed.  相似文献   

12.
强磁场下的固体物理研究进展   总被引:2,自引:0,他引:2  
曹效文 《物理》2002,31(11):696-701
强磁场下的物理研究是一个富有成果的研究领域,40T以下稳态强磁场的研制成功为固体物理研究提供了新的科学机遇。文章简要地介绍强磁场下某些固体物理,其中包括高温超导体的H-T相图和非费米液体行为,德哈斯(de Haas)效应和费米面性质,电子的Wigner结晶及其动力学行为,磁场诱导的相变(如绝缘体-金属和超导转变),多级磁有序,串级自旋密度波和大块材料中的量子霍尔效应等的实验研究的近期进展,希望以此引起人们对国内强磁场下物理研究的关注。  相似文献   

13.
The low-energy physics of the fractional Hall liquid is described in terms of quasiparticles that are qualitatively distinct from electrons. We show, however, that a long-lived electronlike quasiparticle also exists in the excitation spectrum: the state obtained by the application of an electron creation operator to a fractional quantum Hall ground state has a nonzero overlap with a complex, high energy bound state containing an odd number of composite-fermion quasiparticles. The electron annihilation operator similarly couples to a bound complex of composite-fermion holes. We predict that these bound states can be observed through a conductance resonance in experiments involving a tunneling of an external electron into the fractional quantum Hall liquid. A comment is made on the origin of the breakdown of the Fermi liquid paradigm in the fractional Hall liquid.  相似文献   

14.
The model of fermions in a magnetic field interacting via a purely three-body repulsive interaction has attracted interest because it produces, in the limit of short range interaction, the Pfaffian state with non-Abelian excitations. We show that this is part of a rich phase diagram containing a host of fractional quantum Hall states, a composite fermion Fermi sea, and a pairing transition. This is entirely unexpected, because the appearance of composite fermions and fractional quantum Hall effect is ordinarily thought to be a result of strong two-body repulsion. Recent breakthroughs in ultracold atoms have facilitated the realization of such a system, where this physics can be tested.  相似文献   

15.
We study the physics of a rapidly rotating gas of ultracold bosonic atoms. In the limit of very rapid rotation of the trap the system exhibits a fractional quantum Hall regime analogous to that of electrons in the fractional quantum Hall effect. We show that the ground state of the system is a 1/2-Laughlin liquid, a highly correlated atomic liquid. Exotic excitations consisting of localized quasiholes of 1/2 of an atom can be created by focusing lasers at the desired positions. We show how to manipulate these quasiholes in order to probe directly their 1/2-statistics.  相似文献   

16.
The quantum Hall liquid is a novel state of matter with profound emergent properties such as fractional charge and statistics. The existence of the quantum Hall effect requires breaking of the time reversal symmetry caused by an external magnetic field. In this work, we predict a quantized spin Hall effect in the absence of any magnetic field, where the intrinsic spin Hall conductance is quantized in units of 2(e/4pi). The degenerate quantum Landau levels are created by the spin-orbit coupling in conventional semiconductors in the presence of a strain gradient. This new state of matter has many profound correlated properties described by a topological field theory.  相似文献   

17.
Ady Stern 《Annals of Physics》2008,323(1):204-249
The dichotomy between fermions and bosons is at the root of many physical phenomena, from metallic conduction of electricity to super-fluidity, and from the periodic table to coherent propagation of light. The dichotomy originates from the symmetry of the quantum mechanical wave function to the interchange of two identical particles. In systems that are confined to two spatial dimensions particles that are neither fermions nor bosons, coined “anyons”, may exist. The fractional quantum Hall effect offers an experimental system where this possibility is realized. In this paper we present the concept of anyons, we explain why the observation of the fractional quantum Hall effect almost forces the notion of anyons upon us, and we review several possible ways for a direct observation of the physics of anyons. Furthermore, we devote a large part of the paper to non-abelian anyons, motivating their existence from the point of view of trial wave functions, giving a simple exposition of their relation to conformal field theories, and reviewing several proposals for their direct observation.  相似文献   

18.
There has been a great deal of interest over the last two decades on the fractional quantum Hall effect, a novel quantum many-body liquid state of strongly correlated two-dimensional electronic systems in a strong perpendicular magnetic field. The most pronounced fractional quantum Hall states occur at odd denominator filling factors of the lowest Landau level and are described by the Laughlin wave function. It is well known that exact closed-form solutions for many-body wave functions, including the Laughlin wave function, are generally very rare and hard to obtain. In this work we present some exact results corresponding to small systems of electrons in the fractional quantum Hall regime at odd denominator filling factors. Use of Jacobi coordinates is the key tool that facilitates the exact calculation of various quantities. Expressions involving integrals over many variables are considerably simplified with the help of Jacobi coordinates allowing us to calculate exactly various quantities corresponding to systems with several electrons.  相似文献   

19.
Quantum Hall effect (QHE), as a class of quantum phenomena that occur in macroscopic scale, is one of the most important topics in condensed matter physics. It has long been expected that QHE may occur without Landau levels so that neither external magnetic field nor high sample mobility is required for its study and application, Such a QHE free of Landau levels, can appear in topological insulators (TIs) with ferromagnetism as the quantized version of the anomalous Hall effect, i.e., quantum anomalous Hall (QAH) effect. Here we review our recent work on experimental realization of the QAH effect in magnetically doped TIs. With molecular beam epitaxy, we prepare thin films of Cr-doped (Bi,Sb)2Te3 TIs with well- controlled chemical potential and long-range ferromagnetic order that can survive the insulating phase. In such thin films, we eventually observed the quantization of the Hall resistance at h/e2 at zero field, accompanied by a considerable drop in the longitudinal resistance. Under a strong magnetic field, the longitudinal resistance vanishes, whereas the Hall resistance remains at the quantized value. The realization of the QAH effect provides a foundation for many other novel quantum phenomena predicted in TIs, and opens a route to practical applications of quantum Hall physics in low-power-consumption electronics.  相似文献   

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