Change of Electronic Structure Induced by Magnetic Transitions in CeBi

Abstract

The temperature dependence of the electronic structure of CeBi arising from two types of antiferromagnetic transitions based on optical conductivity ($\sigma(\omega)$) was observed. The $\sigma(\omega)$ spectrum continuously and discontinuously changes at 25 and 11 K, respectively. Between these temperatures, two peaks in the spectrum rapidly shift to the opposite energy sides as the temperature changes. Through a comparison with the band calculation as well as with the theoretical $\sigma(\omega)$ spectrum, this peak shift was explained by the energy shift of the Bi $6p$ band due to the mixing effect between the Ce $4f \Gamma_8$ and Bi $6p$ states. The single-layer antiferromagnetic ($+-$) transition from the paramagnetic state was concluded to be of the second order. The marked changes in the $\sigma(\omega)$ spectrum at 11 K, however, indicated the change in the electronic structure was due to a first-order-like magnetic transition from a single-layer to a double-layer ($++--$) antiferromagnetic phase.Comment: 4 pages, to be published in J. Phys. Soc. Jpn. 73 Aug. (2004

Magnetization-governed magnetoresistance anisotropy in the topological semimetal CeBi

“…It reveals that the molecular field coefficient is a sensitive function of temperature at TN/2 < T < TN and remains unchanged at T < TN/2. Optical conductivity [55] and ARPES [56] experiments also detect transitions from p-f mixing to p-f + p-d mixings and from a double Dirac-cone band to a single Dirac-cone band at T » TN/2 when the temperature is lowered. They are consistent with the change of the MR anisotropy revealed here.…”

Infrared spectroscopy under multiextreme conditions: Direct observation of pseudogap formation and collapse in CeSb

“…In CeBi, a similar peak appears in the AF-1 phase. [18] The peak shifts to the low energy side with increasing temperature in the same way as that of CeSb. However, CeBi differs in that it has a metallic σ(ω) spectrum and also a metallic σ 0 value even in the AF-1 phase.…”

“…This same result has been obtained in CeBi at ambient pressure. [18] CeBi has an AF-1 phase even at ambient pressure. In the CeBi case, the pf mixing intensity increases with decreasing temperature.…”