Experimental evidence for composite fermions
Experimental evidence for composite fermions
复制标题
复合费米子的实验证据
DOI：
10.1088/0268-1242/12/5/001
复制
发表时间：
1997
影响因子：
1.9
通讯作者：
R. Willett
中科院分区：
文献类型：
--
作者：
R. Willett
通过发展一个场论模型和相关的实验结果，推进了对极端量子极限下关联二维电子系统的研究。基本的理论构造将相互作用的2D电子转换成被称为复合费米子的准粒子。这种相互作用的准粒子系统的性质最近已经被描述，主要假设费米面应该在大的特定磁场值或填充因子下从准粒子海形成。这个模型可以解释大量的实验数据，包括将分数量子霍尔效应描述为准粒子的整数量子霍尔效应。这篇评论将提出的实验结果，这两个动机，并随后验证了这个模型的方面。下面简要介绍二维电子系统，早期的实验发现，早于和影响复合费米子理论进行检查。的理论建设，特别是在高磁场费米面形成的假设，简要回顾与他们的实验预测。随后的主要理论发展的实验。重点介绍了测量复合费米子费米波矢和平均自由程的声表面波实验，以及证明准粒子在费米面上半经典运动的反点和磁聚焦实验。实验测定的复合费米子有效质量的检查，考虑从直流传输，表面声波和热电测量结果。实验结果进行了总结和潜在的未来研究进行了讨论。
The study of correlated two-dimensional electron systems in the extreme quantum limit has been advanced by development of a field-theoretic model and associated experimental findings. The fundamental theoretical construction transforms the interacting 2D electrons into quasiparticles referred to as composite fermions. The properties of such an interacting quasiparticle system have recently been described, with the main hypothesis that Fermi surfaces should form from the quasiparticle seas at large specific magnetic field values or filling factors. This model serves to provide explanation for an extensive body of experimental data, including description of the fractional quantum Hall effect as the integer quantum Hall effect for the quasiparticles. This review will present the experimental findings which both motivated and subsequently have verified aspects of this model. Following a brief introduction to two-dimensional electron systems, early experimental findings pre-dating and influencing the composite fermion theory are examined. The theoretical construction, and in particular the hypothesis of Fermi surface formation at high magnetic fields, are briefly reviewed with respect to their experimental predictions. Experiments subsequent to the main theoretic developments are then presented. Emphasized are surface acoustic wave experiments which were responsible for measuring the composite fermion Fermi wavevector and mean free path. Also reviewed are antidot and magnetic focusing experiments which demonstrate semiclassical motion of the quasiparticles at the Fermi surface. Experimental determination of the composite fermion effective mass is examined, considering results from measurements in d.c. transport, surface acoustic waves and thermopower. Experimental findings are summarized and potential future studies are discussed.