Calculations of molecular spectral properties, like photodissociation rates and absorption bands, rely on knowledge of the excited state energies of the molecule of interest. Protocols based on the variational quantum eigensolver (VQE) are promising candidates to calculate such energies on emerging noisy intermediate scale quantum (NISQ) computers. The successful implementation of these protocols on NISQ computers, relies on ansätze that can accurately approximate the molecular states and that can be implemented by shallow quantum circuits. In this paper, we introduce the excited qubit-excitation-based adaptive (e-QEB-ADAPT)-VQE protocol to calculate molecular excited state energies. The e-QEB-ADAPT-VQE constructs efficient problem-tailored ansätze by iteratively appending evolutions of qubit excitation operators. The e-QEB-ADAPT-VQE is an adaptation of the QEB-ADAPT-VQE protocol, which is designed to be independent on the choice of an initial reference state. We perform classical numerical simulations for LiH and BeH$_2$ to benchmark the performance of the e-QEB-ADAPT-VQE. We demonstrate that the e-QEB-ADAPT-VQE can construct highly accurate ansätze that require at least an order of magnitude fewer $CNOT$s than standard fixed UCC ansätze, such as the UCCSD and the GUCCSD.
$σ$-VQE: Excited-state preparation of quantum many-body scars with shallow circuits
Center for Nonlinear and Complex Systems, Dipartimento di Scienza e Alta Tecnologia, Università degli Studi dell’Insubria（因苏布里亚大学科学与技术系非线性与复杂系统中心）；Istituto Nazionale di Fisica Nucleare, Sezione di Milano（意大利国家核物理研究所米兰分部）；Instituto de Física Interdisciplinar y Sistemas Complejos (IFISC), UIB–CSIC（巴利阿里群岛大学-西班牙国家研究委员会交叉物理学与复杂系统研究所）
How an Equi-ensemble Description Systematically Outperforms the Weighted-ensemble Variational Quantum Eigensolver
ICGM, Université de Montpellier, CNRS, ENSCM（蒙彼利埃大学，法国国家科学研究中心，国立高等化学学校）；Dipartimento di Ingegneria e Scienze dell’Informazione e Matematica, Università dell’Aquila（阿奎拉大学）
Landscape Analysis of Excited States Calculation over Quantum Computers
Fudan University（复旦大学）；Shanghai Key Laboratory for Contemporary Applied Mathematics, Fudan University（复旦大学现代应用数学上海市重点实验室）；Key Laboratory of Computational Physical Sciences, Ministry of Education（教育部计算物理科学重点实验室）；Shanghai Center for Mathematical Sciences, Fudan University（复旦大学上海数学中心）；Duke University（杜克大学）
Quantum Simulations of Battery Electrolytes with VQE-qEOM and SQD: Active-Space Design, Dissociation, and Excited States of LiPF$_6$, NaPF$_6$, and FSI Salts
Auger Spectroscopy via Generative Quantum Eigensolver: A Quantum Approach to Molecular Excitations
Mitsubishi Chemical Corporation（三菱化学株式会社）；Quantum Computing Center, Keio University（庆应义塾大学量子计算中心）；Mizuho Research & Technologies, Ltd.（瑞穗研究技术有限公司）；NVIDIA（英伟达）
Quantum Chemistry Calculations using Energy Derivatives on Quantum Computers
量子化学计算，如分子性质的预测和化学反应的建模，是近期量子计算机可以展示量子优势的几个关键领域。基于变分量子本征求解器（VQE），提出了一种计算基态和激发态能量对化学体系参数的能量导数的方法.设计了一种混合变分范式下的量子线路的低深度实现，并分析了其计算代价。通过将该方法应用于能量衍生物的量子化学关键应用中，如H $_2$分子的最小能量构型搜索和分子响应性质估计，以及H $_2$ + H $\leftrightarrow$ H + H $_2$反应的过渡态的寻找，展示了该方法的有效性.所得到的结果示出与它们各自的全组态相互作用（FCI）值是完全一致的。
