Benchmarking the exponential ansatz for the Holstein model

Junjie Yang; Zhi-Hao Cui; Ankit Mahajan; Huanchen Zhai; David R Reichman; Garnet Kin-Lic Chan

doi:10.1063/5.0225428

Benchmarking the exponential ansatz for the Holstein model

J Chem Phys. 2024 Sep 14;161(10):104105. doi: 10.1063/5.0225428.

Authors

Junjie Yang¹, Zhi-Hao Cui², Ankit Mahajan², Huanchen Zhai¹, David R Reichman², Garnet Kin-Lic Chan¹

Affiliations

¹ Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125, USA.
² Department of Chemistry, Columbia University, New York, New York 10025, USA.

PMID: 39248383
DOI: 10.1063/5.0225428

Abstract

Polarons are quasiparticles formed as a result of lattice distortions induced by charge carriers. The single-electron Holstein model captures the fundamentals of single polaron physics. We examine the power of the exponential ansatz for the polaron ground-state wavefunction in its coupled cluster, canonical transformation, and (canonically transformed) perturbative variants across the parameter space of the Holstein model. Our benchmark serves to guide future developments of polaron wavefunctions beyond the single-electron Holstein model.