Quantum chemistry Archives - IEEE Transactions on Quantum Engineering

Feedback-Based Quantum Algorithm for Excited States Calculation

January 16, 2026Salahuddin Abdul Rahman, Özkan Karabacak, Rafal WisniewskiQuantum ComputingApproximation algorithms, Convergence, Lyapunov methods, Optimization, Quantum algorithm, Quantum chemistry, Quantum circuit, Quantum computing, Qubit, Stationary state

Abstract: Recently, feedback-based quantum algorithms have been introduced to calculate the ground states of Hamiltonians, inspired by quantum Lyapunov control theory. This article aims to generalize these algorithms to the problem of calculating an eigenstate of a given Hamiltonian, assuming that the lower energy eigenstates are known. To this aim, we propose a new design […]

QuantMark: A Benchmarking API for VQE Algorithms

Thanks to the rise of quantum computers, many variations of the variational quantum eigensolver (VQE) have been proposed in recent times. This is a promising development for real quantum algorithms, as the VQE is a promising algorithm that runs on current quantum hardware. However, the popular method of comparing your algorithm versus a classical baseline […]