Visualizing the Pt Doping Effect on Surface and Electronic Structure in Ir_1−xPt_xTe₂ by Scanning Tunneling Microscopy and Spectroscopy

Abstract

We report on the Pt doping effect on surface and electronic structure in Ir 1−x Pt x Te 2 by scanning tunneling microscopy (STM) and spectroscopy (STS). The surface prepared by cleavage at 4.2 K shows a triangular lattice of topmost Te atoms. The compounds that undergo structural transition have supermodulation with a fixed wave vector q = 2π=5a m (where a m is the lattice constant in the monoclinic phase) despite the different Pt concentrations. The superconducting compounds show patch structures. The surface of the compound that exhibits neither the superconductivity nor the structural transition shows no superstructure. In all doped samples, the dopant is observed as a dark spot in STM images. The tunneling spectra near the dopant show the change in the local density of state at approximately −200 mV. Such microscopic effects of the dopant give us the keys for establishing a microscopic model of this material.

Superconductivity emerging from a stripe charge order in IrTe2 nanoflakes

“…IrTe 2 is one of the TMDCs in vdW structure (Fig. 1b), showing a similar dome-shaped superconducting phase diagram [18][19][20][21][22][23] . IrTe 2 undergoes a stripe charge ordering transition at T s~2 60 K, and by suppressing it with e.g.…”

“…IrTe 2 undergoes a stripe charge ordering transition at T s~2 60 K, and by suppressing it with e.g. chemical doping [18][19][20][21][22][23] the superconducting phase eventually appears, similar to TMDCs hosting the parent CDW orders 4,5,7,8 . The stripe order in IrTe 2 , however, is accompanied by the first-order structural transition involving in-plane Ir-Ir dimerization and interlayer Te-Te depolymerisation 24,25 , which forms stripe patterns with a predominant period of 5a 0 (a 0 , the a axis lattice constant) as depicted in Fig.…”

Nanoscale Superconducting Honeycomb Charge Order in IrTe2

“…In this study, we identify with STM a unprecedented honeycomb charge ordering in nanoscale coexistence with stripe charge orders of IrTe2 [19][20][21][22][23][24] , which is distinct from the hexagonal CDW.…”

“…IrTe2 is currently under extensive investigations due to its unusual electronic properties related to the charge ordering. IrTe2 is an outstanding transition metal dichalcogenide with a charge order (Ir 5d 3+ -Ir 5d 4+ ) transition into 4 stripe phases with a large hysteresis and a nontrivial remnant metallic conductivity [19][20][21][22][23]25,26 .…”

Moiré Superstructure and Dimensional Crossover of 2D Electronic States on Nanoscale Lead Quantum Films

“…2D quantum well states (QWS’s) of Pb films are found to be modulated laterally by the Moiré superstructure at the interface. Furthermore, the substrate features a transition into charge-ordered ground states 13 – 24 with emergent superconductivity 25 – 28 . The stripe charge ordering and the lattice distortion accompanied provide an extra tunability into the 2D electronic states, that is, the 2D-1D dimensional crossover of electronic states.…”