Evolution of Mid-gap States and Residual 3-Dimensionality in La$_{2-x}$Sr$_x$CuO$_4$

TL;DR

This study uses first-principles calculations to analyze how intercell hopping and 3D effects influence ARPES spectra in La$_{2-x}$Sr$_x$CuO$_4$, revealing their significant role in cuprate electronic structure.

Contribution

It demonstrates that including $k_z$-dispersion in theoretical models accurately reproduces key features of ARPES spectra in LSCO, highlighting the importance of 3D effects in cuprate physics.

Findings

Intercell hopping significantly affects ARPES spectra.

3D effects are crucial for understanding cuprate electronic structure.

Salient spectral features are captured when $k_z$-dispersion is included.

Abstract

We have carried out extensive first principles doping-dependent computations of angle-resolved photoemission (ARPES) intensities in La$_{2-x}$Sr$_x$CuO$_4$ (LSCO) over a wide range of binding energies. Intercell hopping and the associated 3-dimensionality, which is usually neglected in discussing cuprate physics, is shown to play a key role in shaping the ARPES spectra. Despite the obvious importance of strong coupling effects (e.g. the presence of a lower Hubbard band coexisting with mid-gap states in the doped insulator), we show that a number of salient features of the experimental ARPES spectra are captured to a surprisingly large extent when effects of $k_z$-dispersion are properly included in the analysis.