Isotope effect on the electron band structure of doped insulators

TL;DR

This study uses quantum Monte-Carlo simulations to analyze how isotope substitution affects the electron band structure and spectral function in doped insulators, revealing wave-vector dependent isotope effects influenced by electron-phonon interactions.

Contribution

It provides the first exact calculations of isotope effects on the band structure of a 2D lattice polaron, highlighting their dependence on interaction parameters.

Findings

Isotope effect varies across different wave-vectors.

Effect depends on electron-phonon interaction strength and radius.

Spectral function also exhibits isotope-dependent features.

Abstract

Applying a continuous-time quantum Monte-Carlo algorithm we calculate the exact coherent band dispersion and the density of states of a two dimensional lattice polaron in the region of parameters where any approximation might fail. We find an isotope effect on the band structure, which is different for different wave-vectors of the Brillouin zone and depends on the radius and strength of the electron-phonon interaction. An isotope effect on the electron spectral function is also discussed.