arXivDaily arXiv每日学术速递 周一至周五更新
arXiv周末暂无论文更新,休息一下吧,周末愉快~~
arXiv 1111.6250cond-mat.str-el
收藏

有限温度下拓扑绝缘体的关联效应

Correlation effects on a topological insulator at finite temperatures

Tsuneya Yoshida, Satoshi Fujimoto, Norio Kawakami

摘要:

将动力学平均场论应用于具有电子关联的广义Bernevig-Hughes-Zhang模型,分析了局域库仑相互作用对拓扑带绝缘体(TBI)的影响.阐明了相关效应如何在有限温度下修改TBI相的电子性质。特别是TBI的带反转特性不可避免地导致了通过重整化效应的光谱间隙的大幅度减小,这导致了自旋霍尔电导率的强烈温度依赖性。我们澄清了从TBI到平凡莫特绝缘体的量子相变,如果它是量子化的,则是具有滞后的一阶相变。这是证实通过相互作用依赖的双重占用和光谱功能。还解决了磁不稳定性问题。所有这些结果意味着,光谱间隙并没有关闭的过渡。

英文摘要:

We analyze the effects of the local Coulomb interaction on a topological band insulator (TBI) by applying the dynamical mean field theory to a generalized Bernevig-Hughes-Zhang model having electron correlations. It is elucidated how the correlation effects modify electronic properties in the TBI phase at finite temperatures. In particular, the band inversion character of the TBI inevitably leads to the large reduction of the spectral gap via the renormalization effect, which results in the strong temperature-dependence of the spin Hall conductivity. We clarify that a quantum phase transition from the TBI to a trivial Mott insulator, if it is nonmagnetic, is of first order with a hysteresis. This is confirmed via the interaction dependence of the double occupancy and the spectral function. A magnetic instability is also addressed. All these results imply that the spectral gap does not close at the transition.

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。

↑