Energy levels estimation on a quantum computer by evolution of a physical quantity
Abstract
We show that the time dependence of mean value of a physical quantity is related with the transition energies of a quantum system. In the case when the operator of a physical quantity anticommutes with the Hamiltonian of a system, studies of the evolution of its mean value allow determining the energy levels of the system. On the basis of the result, we propose a method for determining energy levels of physical systems on a quantum computer. The method opens a possibility to achieve quantum supremacy in solving the problem of finding minimal or maximal energy of Ising model with spatially anisotropic interaction using multi-qubit quantum computers. We apply the method for spin systems (spin in magnetic field, spin chain, Ising model on squared lattice) and realize it on IBM's quantum computers.
Cite
@article{arxiv.2108.08873,
title = {Energy levels estimation on a quantum computer by evolution of a physical quantity},
author = {Kh. P. Gnatenko and H. P. Laba and V. M. Tkachuk},
journal= {arXiv preprint arXiv:2108.08873},
year = {2021}
}