Belozerov A S, Katanin A A, Anisimov V I
M. N. Miheev Institute of Metal Physics, Russian Academy of Sciences, 620108 Yekaterinburg, Russia.
Center for Photonics and 2D Materials, Moscow Institute of Physics and Technology, 141701 Dolgoprudny, Russia.
J Phys Condens Matter. 2021 Jul 19;33(38). doi: 10.1088/1361-648X/ac1090.
We consider electronic and magnetic properties of chromium, a well-known itinerant antiferromagnet, by a combination of density functional theory (DFT) and dynamical mean-field theory (DMFT). We find that electronic correlation effects in chromium, in contrast to its neighbors in the periodic table, are weak, leading to the quasiparticle mass enhancement factor*/≈ 1.2. Our results for local spin-spin correlation functions and distribution of weights of atomic configurations indicate that the local magnetic moments are not formed. Similarly to previous results of DFT at ambient pressure, the non-uniform magnetic susceptibility as a function of momentum possesses close to the wave vector= (0, 0, 2/) (is the lattice constant) sharp maxima, corresponding to Kohn anomalies. We find that these maxima are preserved by the interaction and are not destroyed by pressure. Our calculations qualitatively capture a decrease of the Néel temperature with pressure and a breakdown of itinerant antiferromagnetism at pressure of ∼9 GPa in agreement with experimental data, although the Néel temperature is significantly overestimated because of the mean-field nature of DMFT.
我们通过密度泛函理论(DFT)和动态平均场理论(DMFT)相结合的方法,研究了著名的巡游反铁磁体铬的电子和磁性性质。我们发现,与元素周期表中其相邻元素相比,铬中的电子关联效应较弱,导致准粒子质量增强因子(z^*\approx1.2)。我们关于局部自旋 - 自旋关联函数和原子构型权重分布的结果表明,局部磁矩并未形成。与先前在常压下DFT的结果类似,作为动量函数的非均匀磁化率在接近波矢(\vec{q}=(0,0,2\pi/a))((a)是晶格常数)处具有尖锐的最大值,对应于科恩反常。我们发现,这些最大值在相互作用下得以保留,并且不会因压力而被破坏。我们的计算定性地捕捉到了奈尔温度随压力的降低以及在约9吉帕压力下巡游反铁磁性的破坏,这与实验数据一致,尽管由于DMFT的平均场性质,奈尔温度被显著高估。