Orbital order and fluctuations in the two-leg ladder materials BaFe$_2X_3$ ($X$ = S and Se) and CsFe$_2$Se$_3$

Kou Takubo; Yuichi Yokoyama; Hiroki Wadati; Shun Iwasaki; Takashi Mizokawa; Teak Boyko; Ronny Sutarto; Feizhou He; Kazuki Hashizume; Satoshi Imaizumi; Takuya Aoyama; Yoshinori Imai; Kenya Ohgushi

doi:10.1103/physrevb.96.115157

arXiv · 1704.04864

Orbital order and fluctuations in the two-leg ladder materials BaFe$_2X_3$ ($X$ = S and Se) and CsFe$_2$Se$_3$

Kou Takubo·Yuichi Yokoyama·Hiroki Wadati·Shun Iwasaki·Takashi Mizokawa·Teak Boyko·Ronny Sutarto·Feizhou He·Kazuki Hashizume·Satoshi Imaizumi·Takuya Aoyama·Yoshinori Imai·Kenya Ohgushi

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Abstract

The electronic structure of BaFe$_2X_3$ ($X$ = S and Se) and CsFe$_2$Se$_3$ in which two-leg ladders are formed by the Fe sites are studied by means of x-ray absorption and resonant inelastic x-ray scattering spectroscopy. The x-ray absorption spectra at the Fe L edges for BaFe$_2X_3$ exhibit two components, indicating that itinerant and localized Fe 3$d$ sites coexist. Substantial x-ray linear dichroism (XLD) is observed in polarization dependent spectra, indicating the existence of orbital order or fluctuation in the Fe-ladder even above the Néel temperature $T_N$. Direct exchange interaction along the legs of the Fe-ladder stabilizes the orbital and antiferromagnetic orders in BaFe$_2$S$_3$, while the ferromagnetic molecular orbitals are realized between the rungs in CsFe$_2$Se$_3$.

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Kou Takubo, Yuichi Yokoyama, Hiroki Wadati, Shun Iwasaki, Takashi Mizokawa, Teak Boyko, Ronny Sutarto, Feizhou He, Kazuki Hashizume, Satoshi Imaizumi, Takuya Aoyama, Yoshinori Imai, Kenya Ohgushi. 2017-09-28. Orbital order and fluctuations in the two-leg ladder materials BaFe$_2X_3$ ($X$ = S and Se) and CsFe$_2$Se$_3$. https://doi.org/10.1103/physrevb.96.115157

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