Werner Dobrautz

My name is Werner Dobrautz and welcome to my homepage!

I studied technical physics at Graz University of Technology, specializing in computational solid-state physics. I obtained my PhD in computational quantum chemistry at the Max Planck Institute for Solid State Research and the University of Stuttgart in 2019. My research during my PhD focused on developing innovative quantum Monte Carlo methods in a high-performance computing (HPC) setting to solve strongly correlated electron problems. From 2021 until the end of 2024, I was a Marie Skłodowska-Curie Postdoctoral Fellow at Chalmers University of Technology in Gothenburg, Sweden. My research at Chalmers University and the Wallenberg Centre for Quantum Technologies focused on developing novel quantum computing algorithms to enable realistic electronic structure calculations on current and near-term quantum computing (QC) devices.

I have a strong knowledge of various modern theoretical and computational quantum chemistry and physics methods. I acquired extensive algorithm design and development expertise as the main developer of the publicly available full configuration interaction quantum Monte Carlo (FCIQMC) code NECI during my Ph.D. and consequent PostDoc.

Since December 2024, I am a DRESDEN-concept research group leader jointly appointed at the Center for Scalable Data Analytics and Artificial Intelligence (ScaDS.AI) in Dresden and the Center for Advanced Systems Understanding (CASUS) in Görlitz. In my current role, I am building an AI4Quantum research group that focuses on developing a synergistic HPC+QC approach aided by novel artificial intelligence/deep machine learning methods to enable the computational study of complex quantum systems relevant to the green energy transition. Additionally, my current research focuses on developing innovative quantum Monte Carlo methods and novel quantum computing algorithms to enable realistic electronic structure calculations for strongly correlated electron problems on high-performance computing hardware and near-term quantum computing devices.

News

Dec 18, 2024	Hello Dresden and Görlitz!
Nov 20, 2024	Hej då Sverige -- Goodbye Sweden!
Sep 26, 2024	Talk at the QuantumBW Colloquium on Quantum Computing for Quantum Chemistry
Jul 19, 2024	Poster prize at the Faraday Discussions on Correlated electronic structure
Jul 18, 2024	Talk at the Faraday Discussions on Correlated electronic structure

Selected publications

2024

Quantum

Optimizing Variational Quantum Algorithms with qBang: Efficiently Interweaving Metric and Momentum to Navigate Flat Energy Landscapes

David Fitzek, Robert S. Jonsson, Werner Dobrautz, and Christian Schäfer

Quantum, Apr 2024

arXiv Bib HTML

@article{Fitzek2024,
  title = {Optimizing Variational Quantum Algorithms with qBang: Efficiently Interweaving Metric and Momentum to Navigate Flat Energy Landscapes},
  volume = {8},
  issn = {2521-327X},
  url = {http://dx.doi.org/10.22331/q-2024-04-09-1313},
  doi = {10.22331/q-2024-04-09-1313},
  journal = {Quantum},
  publisher = {Verein zur Forderung des Open Access Publizierens in den Quantenwissenschaften},
  author = {Fitzek, David and Jonsson, Robert S. and Dobrautz, Werner and Sch\"{a}fer, Christian},
  year = {2024},
  month = apr,
  pages = {1313},
  project_devel = {true},
  project_quantum = {true},
  dimensions = {true},
}

JCTC

Toward Real Chemical Accuracy on Current Quantum Hardware Through the Transcorrelated Method

Werner Dobrautz, Igor O. Sokolov, Ke Liao, Pablo López Ríos, Martin Rahm, and 2 more authors

Journal of Chemical Theory and Computation, May 2024

arXiv Bib HTML

@article{Dobrautz2024,
  title = {Toward Real Chemical Accuracy on Current Quantum Hardware Through the Transcorrelated Method},
  volume = {20},
  issn = {1549-9626},
  url = {http://dx.doi.org/10.1021/acs.jctc.4c00070},
  doi = {10.1021/acs.jctc.4c00070},
  number = {10},
  journal = {Journal of Chemical Theory and Computation},
  publisher = {American Chemical Society (ACS)},
  author = {Dobrautz, Werner and Sokolov, Igor O. and Liao, Ke and Ríos, Pablo López and Rahm, Martin and Alavi, Ali and Tavernelli, Ivano},
  year = {2024},
  month = may,
  pages = {4146–4160},
  project_tc = {true},
  project_quantum = {true},
  dimensions = {true},
}

Faraday Diss.

Towards efficient quantum computing for quantum chemistry: reducing circuit complexity with transcorrelated and adaptive ansatz techniques

Erika Magnusson, Aaron Fitzpatrick, Stefan Knecht, Martin Rahm, and Werner Dobrautz

Faraday Discussions, May 2024

arXiv Bib HTML

@article{Magnusson2024,
  title = {Towards efficient quantum computing for quantum chemistry: reducing circuit complexity with transcorrelated and adaptive ansatz techniques},
  volume = {254},
  issn = {1364-5498},
  url = {http://dx.doi.org/10.1039/D4FD00039K},
  doi = {10.1039/d4fd00039k},
  journal = {Faraday Discussions},
  publisher = {Royal Society of Chemistry (RSC)},
  author = {Magnusson, Erika and Fitzpatrick, Aaron and Knecht, Stefan and Rahm, Martin and Dobrautz, Werner},
  year = {2024},
  pages = {402–428},
  project_tc = {true},
  project_quantum = {true},
  dimensions = {true},
}

2023

JCTC
Reference-State Error Mitigation: A Strategy for High Accuracy Quantum Computation of Chemistry

Phalgun Lolur, Mårten Skogh, Werner Dobrautz, Christopher Warren, Janka Biznárová, and 5 more authors

Journal of Chemical Theory and Computation, Jan 2023

Abs arXiv Bib HTML

Decoherence and gate errors severely limit the capabilities of state-of-the-art quantum computers. This work introduces a strategy for reference-state error mitigation (REM) of quantum chemistry that can be straightforwardly implemented on current and near-term devices. REM can be applied alongside existing mitigation procedures, while requiring minimal postprocessing and only one or no additional measurements. The approach is agnostic to the underlying quantum mechanical ansatz and is designed for the variational quantum eigensolver. Up to two orders-of-magnitude improvement in the computational accuracy of ground state energies of small molecules (H2, HeH+, and LiH) is demonstrated on superconducting quantum hardware. Simulations of noisy circuits with a depth exceeding 1000 two-qubit gates are used to demonstrate the scalability of the method.
@article{Lolur2023, doi = {10.1021/acs.jctc.2c00807}, url = {https://doi.org/10.1021/acs.jctc.2c00807}, year = {2023}, month = jan, publisher = {American Chemical Society ({ACS})}, volume = {19}, number = {3}, pages = {783--789}, author = {Lolur, Phalgun and Skogh, M{\aa}rten and Dobrautz, Werner and Warren, Christopher and Bizn{\'{a}}rov{\'{a}}, Janka and Osman, Amr and Tancredi, Giovanna and Wendin, G\"{o}ran and Bylander, Jonas and Rahm, Martin}, title = {Reference-State Error Mitigation: A Strategy for High Accuracy Quantum Computation of Chemistry}, journal = {Journal of Chemical Theory and Computation}, dimensions = {true}, project_quantum = {true}, project_mitigation = {true} }
PRResearch
Orders of magnitude increased accuracy for quantum many-body problems on quantum computers via an exact transcorrelated method

Igor O. Sokolov, Werner Dobrautz, Hongjun Luo, Ali Alavi, and Ivano Tavernelli

Phys. Rev. Res., Jun 2023

Abs arXiv Bib HTML

Transcorrelated methods provide an efficient way of partially transferring the description of electronic correlations from the ground-state wave function directly into the underlying Hamiltonian. In particular, Dobrautz et al. [Phys. Rev. B 99, 075119 (2019)] have demonstrated that the use of momentum-space representation, combined with a nonunitary similarity transformation, results in a Hubbard Hamiltonian that possesses a significantly more “compact” ground-state wave function, dominated by a single Slater determinant. This compactness/single-reference character greatly facilitates electronic structure calculations. As a consequence, however, the Hamiltonian becomes non-Hermitian, posing problems for quantum algorithms based on the variational principle. We overcome these limitations with the Ansatz-based quantum imaginary-time evolution algorithm and apply the transcorrelated method in the context of digital quantum computing. We demonstrate that this approach enables up to four orders of magnitude more accurate and compact solutions in various instances of the Hubbard model at intermediate interaction strength (U/t=4), enabling the use of shallower quantum circuits for wave-function Ansätzes. In addition, we propose a more efficient implementation of the quantum imaginary-time evolution algorithm in quantum circuits that is tailored to non-Hermitian problems. To validate our approach, we perform hardware experiments on the ibmq_lima quantum computer. Our work paves the way for the use of exact transcorrelated methods for the simulations of ab initio systems on quantum computers.
@article{PhysRevResearch.5.023174, title = {Orders of magnitude increased accuracy for quantum many-body problems on quantum computers via an exact transcorrelated method}, author = {Sokolov, Igor O. and Dobrautz, Werner and Luo, Hongjun and Alavi, Ali and Tavernelli, Ivano}, journal = {Phys. Rev. Res.}, volume = {5}, issue = {2}, pages = {023174}, numpages = {19}, year = {2023}, month = jun, publisher = {American Physical Society}, doi = {10.1103/PhysRevResearch.5.023174}, url = {https://link.aps.org/doi/10.1103/PhysRevResearch.5.023174}, dimensions = {true}, project_quantum = {true}, project_tc = {true}, project_hubbard = {true} }