{"title":"挑战自适应量子均衡器的激发态:子空间展开与状态平均策略","authors":"Harper R. Grimsley, Francesco A. Evangelista","doi":"arxiv-2409.11210","DOIUrl":null,"url":null,"abstract":"The prediction of electronic structure for strongly correlated molecules\nrepresents a promising application for near-term quantum computers. Significant\nattention has been paid to ground state wavefunctions, but excited states of\nmolecules are relatively unexplored. In this work, we consider the ADAPT-VQE\nalgorithm, a single-reference approach for obtaining ground states, and its\nstate-averaged generalization for computing multiple states at once. We\ndemonstrate for both rectangular and linear H$_4$, as well as for BeH$_2$, that\nthis approach, which we call MORE-ADAPT-VQE, can make better use of small\nexcitation manifolds than an analagous method based on a single-reference\nADAPT-VQE calculation, q-sc-EOM. In particular, MORE-ADAPT-VQE is able to\naccurately describe both avoided crossings and crossings between states of\ndifferent symmetries. In addition to more accurate excited state energies,\nMORE-ADAPT-VQE can recover accurate transition dipole moments in situations\nwhere traditional ADAPT-VQE and q-sc-EOM struggle. These improvements suggest a\npromising direction toward the use of quantum computers for difficult excited\nstate problems.","PeriodicalId":501226,"journal":{"name":"arXiv - PHYS - Quantum Physics","volume":null,"pages":null},"PeriodicalIF":0.0000,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Challenging Excited States from Adaptive Quantum Eigensolvers: Subspace Expansions vs. State-Averaged Strategies\",\"authors\":\"Harper R. Grimsley, Francesco A. Evangelista\",\"doi\":\"arxiv-2409.11210\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"The prediction of electronic structure for strongly correlated molecules\\nrepresents a promising application for near-term quantum computers. Significant\\nattention has been paid to ground state wavefunctions, but excited states of\\nmolecules are relatively unexplored. In this work, we consider the ADAPT-VQE\\nalgorithm, a single-reference approach for obtaining ground states, and its\\nstate-averaged generalization for computing multiple states at once. We\\ndemonstrate for both rectangular and linear H$_4$, as well as for BeH$_2$, that\\nthis approach, which we call MORE-ADAPT-VQE, can make better use of small\\nexcitation manifolds than an analagous method based on a single-reference\\nADAPT-VQE calculation, q-sc-EOM. In particular, MORE-ADAPT-VQE is able to\\naccurately describe both avoided crossings and crossings between states of\\ndifferent symmetries. In addition to more accurate excited state energies,\\nMORE-ADAPT-VQE can recover accurate transition dipole moments in situations\\nwhere traditional ADAPT-VQE and q-sc-EOM struggle. These improvements suggest a\\npromising direction toward the use of quantum computers for difficult excited\\nstate problems.\",\"PeriodicalId\":501226,\"journal\":{\"name\":\"arXiv - PHYS - Quantum Physics\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":0.0000,\"publicationDate\":\"2024-09-17\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"arXiv - PHYS - Quantum Physics\",\"FirstCategoryId\":\"1085\",\"ListUrlMain\":\"https://doi.org/arxiv-2409.11210\",\"RegionNum\":0,\"RegionCategory\":null,\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"\",\"JCRName\":\"\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"arXiv - PHYS - Quantum Physics","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/arxiv-2409.11210","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
Challenging Excited States from Adaptive Quantum Eigensolvers: Subspace Expansions vs. State-Averaged Strategies
The prediction of electronic structure for strongly correlated molecules
represents a promising application for near-term quantum computers. Significant
attention has been paid to ground state wavefunctions, but excited states of
molecules are relatively unexplored. In this work, we consider the ADAPT-VQE
algorithm, a single-reference approach for obtaining ground states, and its
state-averaged generalization for computing multiple states at once. We
demonstrate for both rectangular and linear H$_4$, as well as for BeH$_2$, that
this approach, which we call MORE-ADAPT-VQE, can make better use of small
excitation manifolds than an analagous method based on a single-reference
ADAPT-VQE calculation, q-sc-EOM. In particular, MORE-ADAPT-VQE is able to
accurately describe both avoided crossings and crossings between states of
different symmetries. In addition to more accurate excited state energies,
MORE-ADAPT-VQE can recover accurate transition dipole moments in situations
where traditional ADAPT-VQE and q-sc-EOM struggle. These improvements suggest a
promising direction toward the use of quantum computers for difficult excited
state problems.