calcQPI: A versatile tool to simulate quasiparticle interference

TL;DR

calcQPI is a versatile computational tool that simulates quasiparticle interference patterns from tight-binding models, aiding the interpretation of scanning tunneling microscopy data to understand electronic structures in quantum materials.

Contribution

It introduces an efficient continuum Green's function-based code for simulating QPI from tight-binding models, improving modeling accuracy over DFT-based methods.

Findings

Enables detailed simulation of QPI patterns

Facilitates analysis of electronic structure in quantum materials

Improves modeling accuracy over DFT-based approaches

Abstract

Quasiparticle interference imaging (QPI) provides a route to characterize electronic structure from real space images acquired using scanning tunneling microscopy. It emerges due to scattering of electrons at defects in the material. The QPI patterns encode details of the $k$-space electronic structure and its spin and orbital texture. Recovering this information from a measurement of QPI is non-trivial, requiring modelling not only of the dominant scattering vectors, but also the overlap of the wave functions with the tip of the microscope. While, in principle, it is possible to model QPI from density functional theory (DFT) calculations, for many quantum materials it is more desirable to model the QPI from a tight-binding model, where inaccuracies of the DFT calculation can be corrected. Here, we introduce an efficient code to simulate quasiparticle interference from tight-binding models using the continuum Green's function method.