A comment on "Different STM Images of the Superstructure on a Clean Si(133)-6x2 Surface" (JETP Letters 105 (8), 477-483 (2017))

TL;DR

This paper critically compares two atomic models of the Si(331) surface, highlighting the importance of stability and electronic structure considerations to clarify their validity and reconcile conflicting interpretations in STM studies.

Contribution

It provides a comprehensive analysis of the stability and electronic structure of the T- and 8P-models, clarifying their differences and resolving ambiguities in previous STM-based interpretations.

Findings

The 8P-model is supported by first-principles calculations.

Stability analysis favors the 8P-model over the T-model.

Electronic structure differences help distinguish the models in STM images.

Abstract

In the recent paper by Teys [JETP Letters 105 (8), 477-483 (2017)], an atomic model for the Si(331) reconstructed surface (hereby referred to as T-model) was proposed on the basis of high-resolution scanning tunneling microscopy (STM) images. While detailing the virtues against previous and abandoned models, the author avoids any reference to the rather distinct 8P-model advocated few weeks earlier by Zhachuk and Teys [R. Zhachuk, S. Teys, Phys. Rev. B 95, 041412 (2017)], casting doubts to his own work. Formulated that way, findings from Ref. [JETP Letters 105 (8), 477-483 (2017)] leave readers of JETP Letters with a partial and confusing view of the problem, and above all, leaves the observations open to ambiguous interpretation. The 8P-model is also based on STM measurements, and unlike the T-model, passed through the scrutiny of first-principles calculations. The present comment reconciles Ref. [JETP Letters 105 (8), 477-483 (2017)] with the literature by supplementing the discussion with a missing and critical account on the stability and electronic structure of the T- versus 8P-models of Si(331).