Quantum Circuits for the Preparation of Spin Eigenfunctions on Quantum Computers

Symmetry

Davide Emilio Galli¹  Mario Motta²  Barbara Jones²  Alessandro Carbone³ 

[1] Dipartimento di Fisica, Università degli Studi di Milano, Via Celoria 16, 20133 Milano, Italy;IBM Quantum, IBM Research Almaden, 650 Harry Road, San Jose, CA 95120, USA;Theory and Simulation of Materials (THEOS), National Centre for Computational Design and Discovery of Novel Materials (MARVEL), École Polytechnique Fédérale de Lausanne, 1015 Lausanne, Switzerland;

关键词: quantum computing;    spin liquids;    eigenstates;    quantum error mitigation;   

DOI  :  10.3390/sym14030624

来源: DOAJ

【 摘 要 】

The application of quantum algorithms to the study of many-particle quantum systems requires the ability to prepare wave functions that are relevant in the behavior of the system under study. Hamiltonian symmetries are important instruments used to classify relevant many-particle wave functions and to improve the efficiency of numerical simulations. In this work, quantum circuits for the exact and approximate preparation of total spin eigenfunctions on quantum computers are presented. Two different strategies are discussed and compared: exact recursive construction of total spin eigenfunctions based on the addition theorem of angular momentum, and heuristic approximation of total spin eigenfunctions based on the variational optimization of a suitable cost function. The construction of these quantum circuits is illustrated in detail, and the preparation of total spin eigenfunctions is demonstrated on IBM quantum devices, focusing on three- and five-spin systems on graphs with triangle connectivity.

【 授权许可】

Unknown