Recently, Li Junxu, a young teacher from the Physics Department, College of Sciences, NEU, made a significant breakthrough in the calculation of perturbation theory based on quantum devices. The related work was published in Science Advances. Science Advances, a leading open-source journal of the American Association for the Advancement of Science (AAAS), is an open, comprehensive scientific journal covering all academic fields.Highly recognized both at home and abroad, it is the top journal in Region 1 of the Chinese Academy of Sciences. Its latest impact factor of the current real-time IF-2022-2023 is 14.98. The first author of this study is Li Junxu, a young teacher from the Physics Department, College of Sciences, NEU, and the corresponding author is Professor Sabre Kais from Purdue University. NEU is a cooperative participant.
Perturbation theory is one of the most commonly used and important methods for solving eigenstates and energy levels in quantum mechanics. In recent years, the development of quantum computing is in full swing, while so far there are few attempts of using quantum computers to calculate perturbation theory. Young teacher Li Junxu from the Physics Department of the College of Sciences of NEU, collaborating with Professor Sabre Kais from Purdue University and Ms. Barbara Jones from IBM, has designed a quantum algorithm which can perform perturbation-related calculations on a quantum computer. Based on the eigenenergy and eigenstate of the given perturbed state, this quantum algorithm can be used to calculate the first-order eigenstate correction and the first-and second-order eigenenergy correction in the perturbed case. The time complexity of this quantum algorithm is lower than that of the classical perturbation theory in the calculation of the second-order energy correction of complex systems. The algorithm was then applied to the extended Hubbard model for numerical simulation based on qiskit, and real-machine tests on an IBM's 27-qubit quantum computer were conducted to verify the feasibility of the algorithm.
The calculation of eigenstates and eigenenergies has been a hot and difficult point in quantum computing in recent years. This study proposes a quantum algorithm based on perturbation theory. Numerical simulation and real-machine tests have further demonstrated the feasibility of this method. It provides a new idea for the design of quantum algorithm.
Paper link: https://www.science.org/doi/10.1126/sciadv.adg4576
Part of quantum circuit design and real-machine test data
