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arXiv 2602.15522math-phmath.MP
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弱相互作用磁性费米气体在Hartree-Fock近似下的霍尔电导普遍性

Universality of the Hall conductivity for a weakly interacting magnetic fermionic gas in the Hartree-Fock approximation

Aalborg University(奥尔堡大学);University of Milan(米兰大学);Sapienza University of Rome(罗马第一大学)

Horia D. Cornean, Emanuela Laura Giacomelli, Domenico Monaco, Mikkel Hviid Thorn

AI总结:

该研究在Hartree-Fock近似下证明了弱相互作用磁性费米气体中霍尔电导的普遍性,展示了自洽解与量子霍尔效应的关联。

摘要:

我们考虑了在外部恒定磁场中相互作用的二维费米气体系统:该系统是扩展的且均匀的,因此假设在磁平移下具有不变性。在Hartree-Fock近似下,我们通过求解一个自洽的固定点方程来直接分析该系统,考虑了热力学极限。我们证明,只要费米子之间的相互作用足够弱,就存在一个唯一的单粒子密度矩阵解自洽条件。通过选择费米-狄拉克分布作为固定点方程中的函数,这种方法可以描述正温度和零温度的情况。在零温度且非相互作用系统的化学势位于自由Landau算符的能隙中时,我们的自洽解是正交投影(一个“相互作用”有效的费米投影)。我们证明,只要相互作用足够弱,其积分态密度随外部磁场线性变化:该变化的斜率是量子霍尔效应在弱相互作用系统中的普遍性,至少在Hartree-Fock近似下可以被Středa公式所体现。

英文摘要:

We consider a two-dimensional gas of interacting fermions in presence of an external constant magnetic field: the system is extended and homogeneous, and thus assumed to be invariant under magnetic translations. Working within the Hartree-Fock approximation, we analyze the system directly in the thermodynamic limit by solving a self-consistent fixed-point equation for the one-particle density matrix. We prove that, provided that the interactions among fermions are sufficiently weak, there exists a unique one-particle density matrix that solves the self-consistency condition. By choosing the Fermi-Dirac distribution as the function in the fixed-point equation, this approach can describe both positive and zero-temperature cases. At zero temperature and when the chemical potential of the non-interacting system lies in a spectral gap of the free Landau operator, our self-consistent solution is an orthogonal projection (an "interacting" effective Fermi projection). We prove that its integrated density of states varies linearly with the external magnetic field, provided the interaction is weak enough: the slope of this variation is quantized and independent of the interaction. According to the Středa formula, this can be seen as yet another expression of the universality of the quantum Hall effect in weakly interacting systems, at least within the Hartree-Fock approximation.

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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