Superconductivity emerging from a stripe charge order in IrTe2 nanoflakes

Abstract

Superconductivity in the vicinity of a competing electronic order often manifests itself with a superconducting dome, centered at a presumed quantum critical point in the phase diagram. This common feature, found in many unconventional superconductors, has supported a prevalent scenario in which fluctuations or partial melting of a parent order are essential for inducing or enhancing superconductivity. Here we present a contrary example, found in IrTe2 nanoflakes of which the superconducting dome is identified well inside the parent stripe charge ordering phase in the thickness-dependent phase diagram. The coexisting stripe charge order in IrTe2 nanoflakes significantly increases the out-of-plane coherence length and the coupling strength of superconductivity, in contrast to the doped bulk IrTe2. These findings clarify that the inherent instabilities of the parent stripe phase are sufficient to induce superconductivity in IrTe2 without its complete or partial melting. Our study highlights the thickness control as an effective means to unveil intrinsic phase diagrams of correlated van der Waals materials.

Stabilization mechanism of molecular orbital crystals in IrTe2

“…In the case of IrTe 2 -nanoflakes that are only a few atomic layers thick, however, the situation has been found to be different. As reported in a very recent study, the superlattice of dimers in these nanoflakes does actually support two-dimensional superconductivity 23 . Superconductivity and ordered dimers are, therefore, not just competing but interacting in a more complex manner.…”

Large-gap insulating dimer ground state in monolayer IrTe2

“…Bulk 1T-IrTe 2 , for examples, exhibits a cascade of charge ordered states upon cooling while maintaining its metalicity 13 . Thin films of 1T-IrTe 2 have also recently been shown to exhibit a superconducting dome as a function of thickness 14,15 . Moreover, the interlayer distance in 1T-IrTe 2 is significantly shorter as compared to typical van der Waals materials [13][14][15][16] , which makes it a good candidate to study the effect of the absence of interlayer coupling into the ML limit.…”

Phase and polarization modulation in two-dimensional In 2 Se 3 via in situ transmission electron microscopy

“…The prevailed 2H-1T and 2H-1T′ phase transitions in 2D transition metal dichalcogenides can also be triggered by alkali metal intercalation, which is beneficial for the electrocatalytic performances of these materials ( 19 ). Structural phase transitions aside, arising from the reduced dimension, a variety of new physical characteristics emerged in 2D materials, such as ferroelectrics ( 20 , 21 ), ferromagnetics ( 22 , 23 ), superconductivity ( 24 , 25 ), etc., which correlate with the phase transition in 2D materials, are currently under intensive study.…”