Effective calculation of the Green's function in the time domain on near-term quantum processors
ORAL
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 two-, three-, and four-site Hubbard models. This
protocol significantly reduces the number of controlled operations when compared to those previously suggested
in literature. Such reduction is quite remarkable when considering the two-site Hubbard model, for which we
show that it is possible to obtain the exact time propagation of the |N ± 1> states by exponentiating one single
Pauli component of the Hamiltonian, allowing us to perform the calculations on an actual superconducting
quantum processor.
and use it to compute the retarded Green’s function for the two-, three-, and four-site Hubbard models. This
protocol significantly reduces the number of controlled operations when compared to those previously suggested
in literature. Such reduction is quite remarkable when considering the two-site Hubbard model, for which we
show that it is possible to obtain the exact time propagation of the |N ± 1> states by exponentiating one single
Pauli component of the Hamiltonian, allowing us to perform the calculations on an actual superconducting
quantum processor.
*This research was supported by an E 3 (EPFL Excellence in Engineering) program fellowship, Grants No. 200021-179312, No. 200021-179138, and NCCR MARVEL, funded by the Swiss National Science Foundation. IBM, the IBM logo, and ibm.com are trademarks of International Business Machines Corp., registered in many jurisdictions worldwide. Other product and service names might be trademarks of IBM or other companies
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Publication: F. Libbi, J. Rizzo, F. Tacchino, N. Marzari and I. Tavernelli, Phys. Rev. Research 4, 043038 (2022)
Presenters
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Francesco Libbi
- Ecole Polytechnique Federale de Lausanne