Orbital-Hybridization-Driven Charge Density Wave Transition in CsV₃ Sb₅ Kagome Superconductor

Area of Science:

• Condensed Matter Physics
• Materials Science
• Quantum Materials

Background:

• Kagome topological superconductors AV3Sb5 exhibit complex phenomena like charge density waves (CDW) and unconventional superconductivity.
• The precise atomic-level mechanisms driving these symmetry-breaking states, including orbital hybridization, remain poorly understood.

Purpose of the Study:

• To elucidate the role of V3d-Sb5p orbital hybridization in mediating the CDW phase transition in CsV3Sb5.
• To identify the specific atomic reconstructions associated with the low-temperature CDW phase.

Main Methods:

• Temperature-dependent X-ray absorption spectroscopy.
• First-principles density functional theory calculations.

Main Results:

• Direct evidence for V3d-Sb5p orbital hybridization participating in the CDW transition.
• Identification of the inverse Star-of-David structure as the preferred atomic reconstruction in the CDW phase.
• Highlighting the critical role of Sb orbitals in mediating the CDW and structural transition.

Conclusions:

• Orbital hybridization is established as the direct mediator of CDW states and structural transitions in CsV3Sb5.
• This research provides fundamental insights into correlated phases in kagome lattices and orbital interactions.
• Offers new avenues for controlling unconventional orders and topology in quantum materials.