English

Effective calculation of the Green's function in the time domain on near-term quantum processors

Quantum Physics 2022-10-21 v1

Abstract

We propose an improved quantum algorithm to calculate the Green's function through real-time propagation, and use it to compute the retarded Green's function for the 2-, 3- and 4-site Hubbard models. This novel protocol significantly reduces the number of controlled operations when compared to those previously suggested in literature. Such reduction is quite remarkable when considering the 2-site Hubbard model, for which we show that it is possible to obtain the exact time propagation of the N±1|N\pm 1\rangle states by exponentiating one single Pauli component of the Hamiltonian, allowing us to perform the calculations on an actual superconducting quantum processor.

Keywords

Cite

@article{arxiv.2203.12372,
  title  = {Effective calculation of the Green's function in the time domain on near-term quantum processors},
  author = {Francesco Libbi and Jacopo Rizzo and Francesco Tacchino and Nicola Marzari and Ivano Tavernelli},
  journal= {arXiv preprint arXiv:2203.12372},
  year   = {2022}
}