Exact electronic states with shallow quantum circuits from global optimisation
Quantum computers promise to revolutionise molecular electronic simulations by overcoming the exponential memory scaling. While electronic wave functions can be represented using a product of fermionic unitary operators, the best ansatz for strongly correlated electronic systems is far from clear. I...
| Main Authors: | , , , |
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| Format: | Journal article |
| Language: | English |
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Springer Nature
2023
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| _version_ | 1826310906172145664 |
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| author | Burton, HGA Marti-Dafcik, D Tew, DP Wales, DJ |
| author_facet | Burton, HGA Marti-Dafcik, D Tew, DP Wales, DJ |
| author_sort | Burton, HGA |
| collection | OXFORD |
| description | Quantum computers promise to revolutionise molecular electronic simulations by overcoming the exponential memory scaling. While electronic wave functions can be represented using a product of fermionic unitary operators, the best ansatz for strongly correlated electronic systems is far from clear. In this contribution, we construct universal wave functions from gate-efficient, spin symmetry-preserving fermionic operators by introducing an algorithm that globally optimises the wave function in the discrete ansatz design and continuous parameter spaces. Our approach maximises the accuracy that can be obtained with near-term quantum circuits and provides a practical route for designing ansätze in the future. Numerical simulations for strongly correlated molecules, including water and molecular nitrogen, and the condensed-matter Hubbard model, demonstrate the improved accuracy of gate-efficient quantum circuits for simulating strongly correlated chemistry. |
| first_indexed | 2024-03-07T08:00:23Z |
| format | Journal article |
| id | oxford-uuid:614896cf-565a-4a89-8ac4-922f2f183e5d |
| institution | University of Oxford |
| language | English |
| last_indexed | 2024-03-07T08:00:23Z |
| publishDate | 2023 |
| publisher | Springer Nature |
| record_format | dspace |
| spelling | oxford-uuid:614896cf-565a-4a89-8ac4-922f2f183e5d2023-09-25T17:42:01ZExact electronic states with shallow quantum circuits from global optimisationJournal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:614896cf-565a-4a89-8ac4-922f2f183e5dEnglishSymplectic ElementsSpringer Nature2023Burton, HGAMarti-Dafcik, DTew, DPWales, DJQuantum computers promise to revolutionise molecular electronic simulations by overcoming the exponential memory scaling. While electronic wave functions can be represented using a product of fermionic unitary operators, the best ansatz for strongly correlated electronic systems is far from clear. In this contribution, we construct universal wave functions from gate-efficient, spin symmetry-preserving fermionic operators by introducing an algorithm that globally optimises the wave function in the discrete ansatz design and continuous parameter spaces. Our approach maximises the accuracy that can be obtained with near-term quantum circuits and provides a practical route for designing ansätze in the future. Numerical simulations for strongly correlated molecules, including water and molecular nitrogen, and the condensed-matter Hubbard model, demonstrate the improved accuracy of gate-efficient quantum circuits for simulating strongly correlated chemistry. |
| spellingShingle | Burton, HGA Marti-Dafcik, D Tew, DP Wales, DJ Exact electronic states with shallow quantum circuits from global optimisation |
| title | Exact electronic states with shallow quantum circuits from global optimisation |
| title_full | Exact electronic states with shallow quantum circuits from global optimisation |
| title_fullStr | Exact electronic states with shallow quantum circuits from global optimisation |
| title_full_unstemmed | Exact electronic states with shallow quantum circuits from global optimisation |
| title_short | Exact electronic states with shallow quantum circuits from global optimisation |
| title_sort | exact electronic states with shallow quantum circuits from global optimisation |
| work_keys_str_mv | AT burtonhga exactelectronicstateswithshallowquantumcircuitsfromglobaloptimisation AT martidafcikd exactelectronicstateswithshallowquantumcircuitsfromglobaloptimisation AT tewdp exactelectronicstateswithshallowquantumcircuitsfromglobaloptimisation AT walesdj exactelectronicstateswithshallowquantumcircuitsfromglobaloptimisation |