arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2302.04620cond-mat.str-el
收藏

掺杂Mott绝缘体中赝能隙的slave fermion(从属费米子)解释

Slave fermion interpretation of the pseudogap in doped Mott insulators

Zhuoqing Long, Jiangfan Wang, Yi-feng Yang

AI总结:

本文应用slave fermion方法研究掺杂Mott绝缘体,发现AFM关联诱导的极化子机制与holon杂化机制相互竞争导致了赝能隙的出现。

摘要:

我们应用最近发展的slave fermion(从属费米子)方法来研究单带Hubbard和Hubbard-Heisenberg模型中的掺杂Mott绝缘体。我们的结果再现了电子能谱中的若干精细特征,并证实了反铁磁(AFM)关联在赝能隙出现中的关键作用。在空穴掺杂下,如果不包含AFM关联,Hubbard模型的局域近似中的电子能谱在Fermi能附近表现出单峰。当通过显式的平均场Heisenberg相互作用引入AFM关联时,在略低的能量处出现了第二个峰,并将另一个峰推向更高的能量,从而在小掺杂下于两个峰之间形成了赝能隙。随着掺杂增加,两个峰迅速增长并最终合并在一起,此时赝能隙不再存在。对掺杂和Heisenberg相互作用强度下能谱演化的详细分析证实,低能峰源于AFM关联背景中holon-spinon(空穴子-自旋子)相互作用导致的极化子机制,而高能峰则源于形成电子准粒子的holon(空穴子)杂化。因此,赝能隙是由极化子机制与杂化机制的相互竞争产生的。我们的结果与先前使用动力学平均场理论及其团簇扩展的数值计算结果吻合良好,但给出了底层物理的更清晰图景。我们的工作为阐明掺杂Mott绝缘体的本质提供了一个有前景的视角,并可作为未来更深入研究的起点。

英文摘要:

We apply the recently developed slave fermion approach to study the doped Mott insulator in the one-band Hubbard and Hubbard-Heisenberg models. Our results produce several subtle features in the electron spectra and confirm the key role of antiferromagnetic (AFM) correlations in the appearance of the pseudogap. Upon hole doping, the electron spectra exhibit a single peak near the Fermi energy in the local approximation of the Hubbard model where AFM correlations are not included. When AFM correlations are included through an explicit mean-field Heisenberg interaction, a second peak emerges at slightly lower energy and pushes the other peak to higher energy, so that a pseudogap emerges between the two peaks at small doping. Both peaks grow rapidly with increasing doping and eventually merge together, where the pseudogap no longer exists. Detailed analyses of the spectral evolution with doping and the strength of the Heisenberg interaction confirm that the lower-energy peak comes from a polaronic mechanism due to the holon-spinon interaction in the AFM-correlated background and the higher-energy peak arises from the holon hybridization to form the electron quasiparticles. Thus, the pseudogap arises from the interplay of the polaronic and hybridization mechanisms. Our results are in good agreement with previous numerical calculations using the dynamical mean-field theory and its cluster extensions, but give a clearer picture of the underlying physics. Our work provides a promising perspective for clarifying the nature of doped Mott insulators and may serve as a starting point for more elaborate investigations in the future.

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。

↑