Understanding Quantum Imaginary Time Evolution and its Variational form
Anglés-Castillo Andreu, Ion Luca, Pandit Tanmoy, Gomez-Lurbe Rafael, Martínez Rodrigo, Garcia-March Miguel Angel
Published: 2025/10/2
Abstract
Many computationally hard problems can be encoded in quantum Hamiltonians. The solution to these problems is given by the ground states of these Hamiltonians. A state-of-the-art algorithm for finding the ground state of a Hamiltonian is the so-called Quantum Imaginary Time Evolution (QITE) which approximates imaginary time evolution by a unitary evolution that can be implemented in quantum hardware. In this paper, we review the original algorithm together with a comprehensive computer program, as well as, the variational version of it.