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Abstract

We report x-ray diffraction studies of the electronic ordering instabilities in the kagome material CsV3Sb5 as a function of temperature and applied magnetic field. Our zero-field measurements between 10 and 120 K reveal an unexpected reorganization of the three-dimensional electronic order in the bulk of CsV3Sb5: At low temperatures, a 2×2×2 superstructure modulation due to electronic order is observed, which upon warming changes to a 2×2×4 superstructure at 60 K. The electronic order-order transition discovered here involves a change in the stacking of electronically ordered V3Sb5 layers, which coincides with anomalies previously observed in magnetotransport measurements. This implies that the temperature-dependent three-dimensional electronic order plays a decisive role for transport properties, which are related to the Berry curvature of the V bands. We also show that the bulk electronic order in CsV3Sb5 breaks the sixfold rotational symmetry of the underlying P6/mmm lattice and perform a crystallographic analysis of the 2×2×2 phase. The latter yields two possible superlattices, namely a staggered star-of-David and a staggered inverse star-of-David structure. Applied magnetic fields up to 10 T have no effect on the x-ray diffraction signal. This, however, does not rule out time-reversal symmetry breaking in CsV3Sb5. © 2022 American Physical Society.