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arXiv 1607.02178cond-mat.str-elcond-mat.mes-hall
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微观模型中分数量子霍尔相位的证据

Evidence of a fractional quantum Hall nematic phase in a microscopic model

N. Regnault, J. Maciejko, S. A. Kivelson, S. L. Sondhi

摘要:

在小动量下,分数量子霍尔(Fractional Quantum Hall,简称FHM)效应中的Girvin-MacDonald-Platzman(GMP)模可以用各向同性FHM液体中的带隙FHM涨落来识别。当GMP模式在接近量子相变到量子氢跃迁的假定点时软化时,这种对应关系将是精确的。出于这些考虑,以及倾斜场实验中存在的一个电子相互作用的证据,我们在填充因子为1/3的最低朗道能级的电子相互作用微观模型中寻找了这种电子相互作用的证据。利用一族各向异性的Laughlin态作为试探波函数,我们发现了各向同性的Laughlin液体和无向同性的Laughlin液体之间的连续量子相变。数值精确对角化的结果还表明,旋转对称性是自发破缺的,该模型的相图包含一个条纹和条纹相。

英文摘要:

At small momenta, the Girvin-MacDonald-Platzman (GMP) mode in the fractional quantum Hall (FQH) effect can be identified with gapped nematic fluctuations in the isotropic FQH liquid. This correspondence would be exact as the GMP mode softens upon approach to the putative point of a quantum phase transition to a FQH nematic. Motivated by these considerations as well as by suggestive evidence of an FQH nematic in tilted field experiments, we have sought evidence of such a nematic FQHE in a microscopic model of interacting electrons in the lowest Landau level at filling factor 1/3. Using a family of anisotropic Laughlin states as trial wave functions, we find a continuous quantum phase transition between the isotropic Laughlin liquid and the FQH nematic. Results of numerical exact diagonalization also suggest that rotational symmetry is spontaneously broken, and that the phase diagram of the model contains both a nematic and a stripe phase.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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