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

• URL: http://arxiv.org/abs/2203.12372v1
• Date: Wed, 23 Mar 2022 12:47:04 GMT
• Title: Effective calculation of the Green's function in the time domain on near-term quantum processors
• Authors: Francesco Libbi, Jacopo Rizzo, Francesco Tacchino, Nicola Marzari, Ivano Tavernelli
• Abstract summary: We show that it is possible to obtain the exact time propagation of the $|Npm 1rangle$ states by exponentiating one single Pauli component of the Hamiltonian. We perform the calculations on an actual superconducting quantum processor.
• Score: 0.0
• License: http://creativecommons.org/licenses/by/4.0/
• 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 $|N\pm 1\rangle$ states by exponentiating one single Pauli component of the Hamiltonian, allowing us to perform the calculations on an actual superconducting quantum processor.

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