Mutual information-assisted adaptive variational quantum eigensolver

Journal Article · Mon Aug 02 00:00:00 EDT 2021 · Quantum Science and Technology

DOI:https://doi.org/10.1088/2058-9565/abdca4· OSTI ID:1763733

Zhang, Zi-Jian ^[1]; Kyaw, Thi Ha ^[2]; Kottmann, Jakob ^[2]; Degroote, Matthias ^[2]; Aspuru-Guzik, Alan ^[2]

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1. Southern Univ. of Science and Technology, Guangdong (China); University of Toronto
2. Univ. of Toronto, ON (Canada)

Adaptive construction of ansatz circuits offers a promising route towards applicable variational quantum eigensolvers on near-term quantum hardware. Those algorithms aim to build up optimal circuits for a certain problem and ansatz circuits are adaptively constructed by selecting and adding entanglers from a predefined pool. In this work, we propose a way to construct entangler pools with reduced size by leveraging classical algorithms. Our method uses mutual information between the qubits in classically approximated ground state to rank and screen the entanglers. The density matrix renormalization group method is employed for classical precomputation in this work. We corroborate our method numerically on small molecules. Our numerical experiments show that a reduced entangler pool with a small portion of the original entangler pool can achieve same numerical accuracy. Here, we believe that our method paves a new way for adaptive construction of ansatz circuits for variational quantum algorithms.

• Research Organization: Univ. of Toronto, ON (Canada)
• Sponsoring Organization: USDOE Office of Science (SC), Advanced Scientific Computing Research (ASCR)
• Grant/Contract Number: SC0019374
• OSTI ID: 1763733
• Journal Information: Quantum Science and Technology, Journal Name: Quantum Science and Technology Journal Issue: 3 Vol. 6; ISSN 2058-9565
• Publisher: IOPscience
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS