Cited by Quantum Equation of Motion with Orbital Optimization for Computing Molecular Properties in Near-Term Quantum Computing

Quantum Equation of Motion with Orbital Optimization for Computing Molecular Properties in Near-Term Quantum Computing DOI

Phillip W. K. Jensen, Erik Rosendahl Kjellgren, Peter Reinholdt

et al.

Journal of Chemical Theory and Computation, Journal Year: 2024, Volume and Issue: 20(9), P. 3613 - 3625

Published: May 3, 2024

Determining the properties of molecules and materials is one premier applications quantum computing. A major question in field how to use imperfect near-term computers solve problems practical value. Inspired by recently developed variants counterpart equation-of-motion (qEOM) approach orbital-optimized variational eigensolver (oo-VQE), we present a algorithm (oo-VQE-qEOM) for calculation molecular computing expectation values on computer. We perform noise-free simulations BeH2 series STO-3G/6-31G/6-31G* basis sets H4 H2O 6-31G using an active space four electrons spatial orbitals (8 qubits) evaluate excitation energies, electronic absorption, and, twisted H4, circular dichroism spectra. demonstrate that proposed can reproduce results conventional classical CASSCF calculations these systems.

Language: Английский

Citations

Understanding and mitigating noise in molecular quantum linear response for spectroscopic properties on quantum computers DOI

Karl Michael Ziems, Erik Rosendahl Kjellgren, Stephan P. A. Sauer

et al.

Chemical Science, Journal Year: 2025, Volume and Issue: 16(10), P. 4456 - 4468

Published: Jan. 1, 2025

The promise of quantum computing to circumvent the exponential scaling chemistry has sparked a race develop algorithms for architecture. However, most works neglect quantum-inherent shot noise, let alone effect current noisy devices. Here, we present comprehensive study linear response (qLR) theory obtaining spectroscopic properties on simulated fault-tolerant computers and present-day near-term hardware. This work introduces novel metrics analyze predict origins noise in algorithm, proposes an Ansatz-based error mitigation technique, reveals significant impact Pauli saving reducing measurement costs subspace methods. Our hardware results using up cc-pVTZ basis set serve as proof principle absorption spectra general approach with accuracy classical multi-configurational Importantly, our exemplify that substantial improvements rates speed are necessary lift computational from concept actual field.

Language: Английский

Citations

Characterizing Conical Intersections of Nucleobases on Quantum Computers DOI

Yuchen Wang, Cameron Cianci, Irma Avdic

et al.

Journal of Chemical Theory and Computation, Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 28, 2025

Hybrid quantum-classical computing algorithms offer significant potential for accelerating the calculation of electronic structure strongly correlated molecules. In this work, we present first quantum simulation conical intersections (CIs) in a biomolecule, cytosine, using superconducting computer. We apply contracted eigensolver (CQE)─with comparisons to conventional variational deflation (VQD)─to compute near-degenerate ground and excited states associated with intersection, key feature governing photostability DNA RNA. The CQE is based on an exact ansatz many-electron molecules absence noise─a critically important property resolving at CIs. Both methods demonstrate promising accuracy when compared diagonalization, even noisy intermediate-scale computers, highlighting their advancing understanding photochemical photobiological processes. ability simulate these critical our knowledge biological processes like repair mutation, implications molecular biology medical research.

Language: Английский

Citations

Which Options Exist for NISQ-Friendly Linear Response Formulations? DOI

Karl Michael Ziems, Erik Rosendahl Kjellgren, Peter Reinholdt

et al.

Journal of Chemical Theory and Computation, Journal Year: 2024, Volume and Issue: 20(9), P. 3551 - 3565

Published: April 25, 2024

Linear response (LR) theory is a powerful tool in classic quantum chemistry crucial to understanding photoinduced processes and biology. However, performing simulations for large systems the case of strong electron correlation remains challenging. Quantum computers are poised facilitate simulation such systems, recently, linear formulation (qLR) was introduced [Kumar et al., J. Chem. Theory Comput. 2023, 19, 9136–9150]. To apply qLR near-term beyond minimal basis set, we here introduce resource-efficient theory, using truncated active-space version multiconfigurational self-consistent field LR ansatz. Therein, investigate eight different formalisms that utilize novel operator transformations allow equations be performed on hardware. Simulating excited state potential energy curves absorption spectra various test cases, identify two promising candidates, dubbed "proj LRSD" "all-proj LRSD".

Language: Английский

Citations

Subspace Methods for the Simulation of Molecular Response Properties on a Quantum Computer DOI

Peter Reinholdt, Erik Rosendahl Kjellgren, Juliane Holst Fuglsbjerg

et al.

Journal of Chemical Theory and Computation, Journal Year: 2024, Volume and Issue: 20(9), P. 3729 - 3740

Published: May 1, 2024

We explore Davidson methods for obtaining excitation energies and other linear response properties within the recently developed quantum self-consistent (q-sc-LR) method. Davidson-type allow only a few selected without explicitly constructing electronic Hessian since they require ability to perform Hessian-vector multiplications. apply method calculate of hydrogen chains (up H10) analyze aspects statistical noise computing on simulators. Additionally, we such as static polarizabilities H2, LiH, H2O, OH–, NH3, show that unitary coupled cluster outperforms classical projected molecular systems with strong correlation. Finally, formulate damped (complex) response, application nitrogen K-edge X-ray absorption ammonia, C6 coefficients NH3.

Language: Английский

Citations

Quantum Davidson algorithm for excited states DOI

Nikolay V. Tkachenko, Łukasz Cincio, Alexander I. Boldyrev

et al.

Quantum Science and Technology, Journal Year: 2024, Volume and Issue: 9(3), P. 035012 - 035012

Published: April 4, 2024

Abstract Excited state properties play a pivotal role in various chemical and physical phenomena, such as charge separation light emission. However, the primary focus of most existing quantum algorithms has been ground state, seen phase estimation variational eigensolver (VQE). Although VQE-type methods have extended to explore excited states, these grapple with optimization challenges. In contrast, Krylov subspace (QKS) method introduced address both positioning itself cost-effective alternative estimation. conventional QKS methodologies depend on pre-generated through real or imaginary-time evolutions. This is inherently expansive can be plagued issues like slow convergence numerical instabilities, often leading relatively deep circuits. Our research presents an economic algorithm, which we term Davidson (QDavidson) algorithm. innovation hinges iterative expansion incorporation pre-conditioner within framework. By using residues eigenstates expand subspace, manage formulate compact that aligns closely exact solutions. paves way for more rapid comparison other techniques, Lanczos. Using simulators, employ novel QDavidson algorithm delve into systems, spanning from Heisenberg spin model molecules. Compared methods, not only converges swiftly but also demands significantly shallower circuit. efficiency establishes pragmatic tool elucidating computing platforms.

Language: Английский

Citations

Simulating Vibronic Spectra by Direct Application of Doktorov Formulas on a Superconducting Quantum Simulator DOI

R. Hernández, Benoı̂t Champagne, Armand Soldera

et al.

The Journal of Physical Chemistry A, Journal Year: 2024, Volume and Issue: 128(21), P. 4369 - 4377

Published: May 16, 2024

In this work, a direct quantum implementation of the Doktorov formulas for calculating vibronic spectrum molecules under harmonic approximation is presented. It applied to three-atom H2O, SO2, ClO2, HS2, and ZnOH. The method solves classically hard problem estimating Franck–Condon (FC) factors by using Duschinsky matrices as only input via circuit. This has advantage avoiding basis changes, artificial squeezing parameters, symmetry dependencies. other words, it general that can easily be generalized bigger molecules. results are compared with algorithms classical anharmonic algorithms. Furthermore, circuit requirements studied in order estimate its applicability on real superconducting hardware.

Language: Английский

Citations

Quantum Computation of Conical Intersections on a Programmable Superconducting Quantum Processor DOI

Shoukuan Zhao,

Diandong Tang,

Xiaoxiao Xiao

et al.

The Journal of Physical Chemistry Letters, Journal Year: 2024, Volume and Issue: 15(28), P. 7244 - 7253

Published: July 8, 2024

Conical intersections (CIs) are pivotal in many photochemical processes. Traditional quantum chemistry methods, such as the state-average multiconfigurational face computational hurdles solving electronic Schrödinger equation within active space on classical computers. While computing offers a potential solution, its feasibility studying CIs, particularly real hardware, remains largely unexplored. Here, we present first successful realization of hybrid quantum-classical complete self-consistent field method based variational eigensolver (VQE-SA-CASSCF) superconducting processor. This approach is applied to investigate CIs two prototypical systems─ethylene (C

Language: Английский

Citations

Quantum computing and chemistry DOI

Jared D. Weidman, Manas Sajjan,

Camille A. Mikolas

et al.

Cell Reports Physical Science, Journal Year: 2024, Volume and Issue: 5(9), P. 102105 - 102105

Published: July 15, 2024

As the year-to-year gains in speeds of classical computers continue to taper off, computational chemists are increasingly examining quantum computing as a possible route achieve greater performance. Quantum computers, built upon properties superposition, interference, and entanglement bits, offer, principle, possibility outperform for solving many important classes problems. In field chemistry, algorithm development offers promising propositions classically intractable problems areas such electronic structure, chemical dynamics, spectroscopy, cheminformatics. However, physical implementations still their infancy have yet useful computations. Still, software chemistry is highly active area research. this perspective, we summarize recent progress algorithms, hardware, software, describe challenges that remain applications.

Language: Английский

Citations

Self-consistent Quantum Linear Response with a Polarizable Embedding Environment DOI

Peter Reinholdt, Erik Rosendahl Kjellgren, Karl Michael Ziems

et al.

The Journal of Physical Chemistry A, Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 23, 2025

Quantum computing presents a promising avenue for solving complex problems, particularly in quantum chemistry, where it could accelerate the computation of molecular properties and excited states. This work focuses on excitation energies with hybrid quantum-classical algorithms near-term devices, combining linear response (qLR) method polarizable embedding (PE) environment. We employ self-consistent operator manifold (q-sc-LR) top unitary coupled cluster (UCC) wave function combination Davidson solver. The latter removes need to construct entire electronic Hessian, improving computational efficiency when going toward larger molecules. introduce new superposition-state-based technique compute Hessian-vector products show that this approach is more resilient noise than our earlier gradient-based approach. demonstrate performance PE-UCCSD model systems such as butadiene para-nitroaniline water find delivers comparable accuracy classical PE-CCSD methods simple closed-shell systems. also explore challenges posed by hardware propose error mitigation techniques maintain accurate results noisy computers.

Language: Английский

Citations