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  • Letter
  • Open Access

Nature of the high-pressure insulating state in Sr2IrO4: Mott picture

Guoren Zhang1,2,3, Hanif Hadipour4, and Eva Pavarini3

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Phys. Rev. B 111, L121101 – Published 4 March, 2025

DOI: https://doi.org/10.1103/PhysRevB.111.L121101

Abstract

At ambient pressure, the t2g5 layered perovskite Sr2IrO4 is a correlated small-gap insulator. In the Mott picture, applying uniform pressure should therefore quickly close the gap; experimentally, however, the insulating state persists even under extreme pressures, suggesting that a mechanism other than Mott is at work. Yet, given the complexity of the system, it is unclear to what extent the Mott picture can be really excluded. Here, we thus reexamine the problem. We show that, surprisingly, the pressure-induced enhancement of the screened Coulomb interaction—combined with lattice distortions and spin-orbit driven jeff=1/2 orbital ordering—can hold the system close to the metal-insulator transition up to very high pressure.

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References (58)

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Phys. Rev. B 111, L121101– Published 4 March, 2025
  • Received 3 September 2024
  • Revised 6 February 2025
  • Accepted 11 February 2025
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