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Related papers: Quantum Equation-of-Motion Method with Single, Dou…

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We present the first demonstration of an end-to-end pipeline with quantum error correction (QEC) for a quantum computation of the electronic structure of molecular systems. We calculate the ground-state energy of molecular hydrogen, using…

A new state specific correlation correction to configuration interaction singles (CIS) excitation energies is preseted using coupled cluster perturbation theory (CCPT). General expressions for CIS-CCPT are derived and expanded explicitly to…

Chemical Physics · Physics 2015-06-19 Jason N. Byrd , Victor F. Lotrich , Rodney J. Bartlett

The double ionization potential (DIP) equation-of-motion (EOM) coupled-cluster (CC) method with 4-hole--2-particle (4$h$-2$p$) excitations on top of the CC with singles, doubles, and triples calculation, abbreviated as…

Near-term quantum computers have been built as intermediate-scale quantum devices and are fragile against quantum noise effects, namely, NISQ devices. Traditional quantum-error-correcting codes are not implemented on such devices and to…

Quantum Physics · Physics 2024-03-18 Yusuke Hama , Hirofumi Nishi

Inelastic effects in the Coulomb blockade and Kondo regimes of electron transport through molecular junctions are considered within a simple nonequilibrium equation-of-motion (EOM) approach. The scheme is self-consistent, and can…

Mesoscale and Nanoscale Physics · Physics 2007-07-02 Michael Galperin , Abraham Nitzan , Mark A. Ratner

We extend the CIPSI-driven CC($P$;$Q$) methodology [K. Gururangan et al., J. Chem. Phys. 155 (2021) 174114], in which the leading higher-than-doubly excited determinants are identified using the selected configuration interaction (CI)…

Chemical Physics · Physics 2026-02-24 Swati S. Priyadarsini , Karthik Gururangan , Piotr Piecuch

Quantum optimization has emerged as a promising frontier of quantum computing, providing novel numerical approaches to mathematical optimization problems. The main goal of this paper is to facilitate interdisciplinary research between the…

Optimization and Control · Mathematics 2025-09-05 Alexey Bochkarev , Raoul Heese , Sven Jäger , Philine Schiewe , Anita Schöbel

We introduce a hybrid method for dielectric-metal composites that describes the dynamics of the metallic system classically whilst retaining a quantum description of the dielectric. The time-dependent dipole moment of the classical system…

Mesoscale and Nanoscale Physics · Physics 2016-10-05 Ryan J. McMillan , Lorenzo Stella , Myrta Grüning

We present a generalized equations-of-motion method that efficiently calculates energy spectra and matrix elements for algebraic models. The method is applied to a 5-dimensional quartic oscillator that exhibits a quantum phase transition…

Nuclear Theory · Physics 2008-11-26 S. Y. Ho , G. Rosensteel , D. J. Rowe

In computational molecular science, calculation of electrostatic interactions involving charged atoms - the strongest interactions in condensed phases, is a major bottleneck. We propose a quantum-classical algorithm for fast, yet, accurate…

Quantum Physics · Physics 2026-02-18 Mansur Ziiatdinov , Igor Novikov , Farid Ablayev , Valeri Barsegov

A quantum master equation (QME) is derived for the many-body density matrix of an open current-carrying system weakly coupled to two metal leads. The dynamics and the steady-state properties of the system for arbitrary bias are studied…

Statistical Mechanics · Physics 2016-08-31 Upendra Harbola , Massimiliano Esposito , Shaul Mukamel

We propose an excited-state molecular dynamics simulation method based on variational quantum algorithms at a computational cost comparable to that of ground-state simulations. We utilize the feature that excited states can be obtained as…

Chemical Physics · Physics 2023-03-02 Hirotoshi Hirai

Cavity quantum electrodynamics (QED) generalizations of time-dependent (TD) density functional theory (DFT) and equation-of-motion (EOM) coupled-cluster (CC) theory are used to model small molecules strongly coupled to optical cavity modes.…

Chemical Physics · Physics 2023-07-19 Marcus D. Liebenthal , Nam Vu , A. Eugene DePrince

Quantum Error Mitigation (QEM) enables the extraction of high-quality results from the presently-available noisy quantum computers. In this approach, the effect of the noise on observables of interest can be mitigated using multiple…

Quantum Physics · Physics 2023-11-23 Ivan Henao , Jader P. Santos , Raam Uzdin

A major difficulty in quantum simulation is the adequate treatment of a large collection of entangled particles, synonymous with electron correlation in electronic structure theory, with coupled cluster (CC) theory being the leading…

Chemical Physics · Physics 2024-06-06 Zachary W. Windom , Daniel Claudino , Rodney J. Bartlett

Many-body techniques based on the double unitary coupled cluster ansatz (DUCC) can be used to downfold electronic Hamiltonians into low-dimensional active spaces. It can be shown that the resulting dimensionality reduced Hamiltonians are…

Quantum Physics · Physics 2020-01-29 Nicholas P. Bauman , Guang Hao Low , Karol Kowalski

It is exponentially hard to simulate quantum systems by classical algorithms, while quantum computer could in principle solve this problem polynomially. We demonstrate such an quantum-simulation algorithm on our NMR system to simulate an…

Quantum Physics · Physics 2009-07-22 Jiangfeng Du , Nanyang Xu , Xinhua Peng , Pengfei Wang , Sanfeng Wu , Dawei Lu

We introduce a new method for the computation of the transition moments between the excited electronic states based on the expectation value formalism of the coupled cluster theory [B. Jeziorski and R. Moszynski, Int. J. Quant. Chem. 48,…

Chemical Physics · Physics 2017-02-01 Aleksandra Tucholska , Michal Lesiuk , Robert Moszynski

The excitation of vibrational modes in molecules affects the outcome of chemical reactions, for example by providing molecules with sufficient energy to overcome activation barriers. In this work, we introduce a quantum algorithm for…

Quantum Physics · Physics 2021-12-01 Soran Jahangiri , Juan Miguel Arrazola , Nicolás Quesada , Alain Delgado

In bulk systems, molecules are routinely identified by their vibrational spectrum using Raman or infrared spectroscopy. In recent years, vibrational excitation lines have been observed in low-temperature conductance measurements on single…

Mesoscale and Nanoscale Physics · Physics 2010-02-25 Johannes S. Seldenthuis , Herre S. J. van der Zant , Mark A. Ratner , Joseph M. Thijssen