This readme file was generated on 2023-12-13.

GENERAL INFORMATION

Title of Dataset: 
Data for: State preparation in quantum algorithms for fragment-based quantum chemistry

Description of Dataset: 
State preparation for quantum algorithms is crucial for achieving high accuracy in quantum chemistry and competing with classical algorithms. The localized active space unitary coupled cluster (LAS-UCC) algorithm iteratively loads a fragment-based multireference wave function onto a quantum computer. In this study, we compare two state preparation methods, quantum phase estimation (QPE) and direct initialization (DI), for each fragment. We test the two state preparation methods on three systems, ranging from a model system, a set of interacting hydrogen molecules, to more realistic chemical problems, like the C-C double bond breaking in trans-butadiene, and the spin ladder in a bimetallic system. We analyze the impact of QPE parameters, such as the number of ancilla qubits and Trotter steps, on the prepared state. We find a trade-off between the methods, where DI requires fewer resources for smaller fragments, while QPE is more efficient for larger fragments. Our resource estimates highlight the benefits of system fragmentation in state preparation for subsequent quantum chemical calculations. These findings have broad applications for preparing multireference quantum chemical wave functions on quantum circuits, that can be used for realistic chemical applications.

Author/Principal Investigator Information
Name: Ruhee D’Cunha
ORCID: https://orcid.org/0000-0002-1866-5786
Institution: University of Chicago
Address: 5735 S Ellis Avenue, Chicago, IL, USA  60637 
Email: rdcunha@uchicago.edu

Author/Associate or Co-investigator Information
Name: Laura Gagliardi
ORCID: 
Institution: University of Chicago
Address: 5735 S Ellis Avenue, Chicago, IL, USA  60637
Email: lgagliardi@uchicago.edu

Author/Alternate Contact Information
Name: Matthew R. Hermes
ORCID: https://orcid.org/0000-0001-7807-2950
Institution: University of Chicago
Address: 5735 S Ellis Avenue, Chicago, IL, USA  60637
Email: mrhermes@uchicago.edu

Date of data collection: 

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Information about funding sources that supported the collection of the data: 
Department of Energy: DE-AC0206CH11357
National Science Foundation: NSF OMA-2121044 


SHARING/ACCESS INFORMATION

Licenses/restrictions placed on the data: 
Creative Commons Attribution-NoDerivs 4.0 International (CC BY-ND 4.0) license
https://creativecommons.org/licenses/by-nd/4.0/ 

Links to publications that cite or use the data:
https://arxiv.org/abs/2305.18110 

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Recommended citation for this dataset: 
D’Cunha, R.  (2023).  Data for: State preparation in quantum algorithms for fragment-based quantum chemistry [Data set].  Knowledge@UChicago.  https://doi.org/10.6082/uchicago.9794


DATA & FILE OVERVIEW

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METHODOLOGICAL INFORMATION

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DATA-SPECIFIC INFORMATION FOR:

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