Single Particle Spectrum of Doped $\mathrm{C}_{20}\mathrm{H}_{12}$-Perylene

TL;DR

This study uses Hamiltonian Monte Carlo with the Hubbard model to analyze the single-particle spectrum of doped perylene, revealing significant interaction effects at high chemical potentials relevant for organic electronic applications.

Contribution

It introduces a variational basis and contour deformation techniques to study doped perylene's spectrum within the Hubbard model, addressing sign problems and discretization effects.

Findings

Significant deviation from non-interacting spectra at high chemical potentials

Effective mitigation of sign problem through contour deformation

Finite interaction effects are prominent in the spectrum analysis

Abstract

We present a Hamiltonian Monte Carlo study of doped perylene $\mathrm{C}_{20}\mathrm{H}_{12}$ described with the Hubbard model. Doped perylene can be used for organic light-emitting diodes (OLEDs) or as acceptor material in organic solar cells. Therefore, central to this study is a scan over charge chemical potential. A variational basis of operators allows for the extraction of the single-particle spectrum through a mostly automatic fitting procedure. Finite chemical potential simulations suffer from a sign problem which we ameliorate through contour deformation. The on-site interaction is kept at $U/\kappa = 2$. Discretization effects are handled through a continuum limit extrapolation. Our first-principles calculation shows significant deviation from non-interacting results especially at large chemical potentials.