Superconductivity Induced by Bond Breaking in the Triangular Lattice of IrTe2

TL;DR

This paper demonstrates that breaking Ir-Ir bonds in IrTe2-based compounds induces superconductivity, highlighting the role of structural fluctuations near a critical point in a narrow doping range.

Contribution

It reveals that bond breaking in IrTe2 leads to a structural critical point and induces superconductivity, a novel mechanism in layered iridium compounds.

Findings

Superconductivity at Tc = 3.1 K appears after bond breaking.

A structural critical point exists at xc = 0.035 in Ir1-xPtxTe2.

Structural fluctuations are involved in the emergence of superconductivity.

Abstract

IrTe2, a layered compound with a triangular iridium lattice, exhibits a structural phase transition at approximately 250 K. This transition is characterized by the formation of Ir-Ir bonds along the b-axis. We found that the breaking of Ir-Ir bonds that occurs in Ir1-xPtxTe2 results in the appearance of a structural critical point in the T = 0 limit at xc = 0.035. Although both IrTe2 and PtTe2 are paramagnetic metals, superconductivity at Tc = 3.1 K is induced by the bond breaking in a narrow range of x > xc in Ir1-xPtxTe2. This result indicates that structural fluctuations can be involved in the emergence of superconductivity.