Stabilization of orbital crystals in IrTe2 revealed!

Electronic order and superconductivity appear to be closely related in many materials. Doped IrTe₂ is such as case. In these compounds the electronic order has been particularly puzzling and especially the stabilization mechanism remained hidden. Combining high-pressure synchrotron studies with density functional theory, we uncovered that localized molecular orbitals are stabilized by distortions of the Ir-Te-Ir bond angle. When the electronic order sets in, this bond angle decreases dramatiocally, leading to a stabilization of a multicenter molecular orbital bond. This unusual mechanism of local bond formation in an itinerant material provides a natural explanation for the different electronic orders in IrTe₂. It further illustrates an interesting way how electrons can couple with the lattice and is most likely relevant for the superconductivity in this material.

Original publication:
Stabilization mechanism of molecular orbital crystals in IrTe2,
Tobias Ritschel, Quirin Stahl, Maximilian Kusch, Jan Trinckauf, Gaston Garbarino,
Volodymyr Svitlyk, Mohamed Mezouar, Junjie Yang, Sang-Wook Cheong & Jochen Geck,
Commun. Phys. 5, 325 (2022)