Accurate and efficient ab initio Quantum Chemistry calculations on current and near-term noisy intermediate-scale Quantum Computers for relevant chemical problems

Project Information

QC-SQUARED

Grant agreement ID: 101062864

DOI

10.3030/101062864

Project closed

EC signature date 14 June 2022

Start date 1 July 2022

End date 30 November 2024

Funded under

• Marie Skłodowska-Curie Actions (MSCA)

Total cost

No data

EU contribution

€ 222 727,68

Coordinated by

CHALMERS TEKNISKA HOGSKOLA AB
Sweden

Periodic Reporting for period 1 - QC-SQUARED (Accurate and efficient ab initio Quantum Chemistry calculations on current and near-term noisy intermediate-scale Quantum Computers for relevant chemical problems)

Reporting period: 2022-07-01 to 2024-11-30

Summary of the context and overall objectives of the project

Quantum computing has the potential to revolutionize computational chemistry and materials science, offering the possibility of solving complex problems that are intractable for classical computers. However, current quantum hardware faces challenges such as noise, limited qubit availability, and shallow circuit depths, which hinder the practical implementation of quantum chemistry simulations. The QC-SQUARED project, funded under the Marie Skłodowska-Curie Actions (MSCA) Postdoctoral Fellowship, aimed to overcome these limitations by developing advanced quantum algorithms optimized for noisy intermediate-scale quantum (NISQ) devices.

The project’s primary objective was to enable accurate and efficient quantum chemistry simulations by leveraging transcorrelated quantum algorithms and adaptive variational quantum imaginary time evolution (AVQITE). The transcorrelated approach incorporates electron correlation effects directly into the Hamiltonian, significantly reducing the required computational resources while maintaining accuracy. This makes it possible to achieve high-precision quantum chemistry calculations with fewer qubits, bringing practical quantum simulations closer to reality. Additionally, AVQITE was developed to optimize quantum circuit depth dynamically, reducing the impact of hardware noise and improving algorithmic stability.

Another key focus of the project was benchmarking these methods against state-of-the-art classical computational techniques. Simulations were performed on IBM quantum processors to validate the effectiveness of the transcorrelated method and AVQITE in real-world quantum computing environments. These experiments demonstrated that quantum chemistry calculations could be performed with improved noise resilience and reduced computational overhead, making them more viable on near-term quantum devices.

The project also contributed significantly to the scientific community by publishing research in high-impact journals and presenting findings at international conferences, including the APS March Meeting and Faraday Discussions. Additionally, workshops and training sessions were organized to share insights and advance the adoption of quantum computing techniques for chemistry applications.

The results of QC-SQUARED are expected to impact multiple fields, including materials discovery, drug design, and sustainable energy solutions. By developing more efficient quantum algorithms, the project lays the foundation for future breakthroughs in quantum chemistry and strengthens Europe's leadership in quantum computing research. Future work will focus on scaling these methods to larger molecular systems, integrating them into industry-relevant workflows, and exploring commercialization opportunities to bridge the gap between academic research and real-world applications.

Work performed from the beginning of the project to the end of the period covered by the report and main results achieved so far

The QC-SQUARED project focused on developing quantum algorithms for electronic structure calculations, optimizing them for noisy intermediate-scale quantum (NISQ) devices. The work combined theoretical advancements, algorithmic implementations, hardware benchmarking, and validation against classical methods.

A major achievement was the development of transcorrelated quantum algorithms, which integrate electron correlation effects directly into the Hamiltonian. This approach significantly reduced computational complexity, allowing high-accuracy simulations with fewer qubits. The adaptive variational quantum imaginary time evolution (AVQITE) method was implemented to optimize circuit depth and improve noise resilience, making quantum chemistry calculations feasible on current quantum hardware.

Extensive benchmarking was performed on IBM quantum processors, demonstrating that transcorrelated methods improve computational accuracy while reducing the impact of noise. By applying these algorithms to small molecular systems, the project showed that quantum simulations could achieve results comparable to state-of-the-art classical approaches. The successful execution of electronic structure calculations on real quantum devices validated the theoretical models and confirmed the feasibility of transcorrelated quantum chemistry.

Beyond algorithm development, theoretical validation was carried out through extensive comparisons with classical computational methods, confirming the advantages of the transcorrelated approach. The findings showed that the transcorrelated method allows for more compact wavefunctions and shallower quantum circuits, making it a promising solution for near-term quantum computing applications in chemistry.

The project also contributed to the broader scientific community through high-impact publications and conference presentations. Research findings were published in leading journals and presented at major conferences such as the APS March Meeting and Faraday Discussions. Additionally, seminars and workshops were conducted to share insights with researchers in quantum computing and computational chemistry.

In summary, the project successfully implemented and validated transcorrelated quantum algorithms, demonstrated their performance on real quantum hardware, and disseminated results to advance the field of quantum chemistry. These achievements bring practical quantum computing for chemistry closer to reality, enabling more accurate simulations on near-term devices and laying the foundation for future advancements.

Progress beyond the state of the art and expected potential impact (including the socio-economic impact and the wider societal implications of the project so far)

The QC-SQUARED project has advanced the field of quantum computing for quantum chemistry by developing and implementing transcorrelated quantum algorithms that significantly improve accuracy while reducing computational resource requirements. These advancements go beyond the state of the art by enabling more efficient simulations of electronic structure problems on noisy intermediate-scale quantum (NISQ) devices, a critical step toward practical quantum advantage in chemistry and materials science.

One of the most significant breakthroughs of the project was the successful integration of the transcorrelated method with variational quantum imaginary time evolution (AVQITE). By embedding electron correlation effects directly into the quantum Hamiltonian, the project reduced the number of qubits required for high-accuracy calculations. This approach enabled more compact wavefunctions, leading to shallower quantum circuits and improved computational efficiency, making complex chemical simulations feasible on existing quantum hardware. This represents a major step forward compared to conventional variational quantum eigensolver (VQE) methods, which struggle with noise and circuit depth limitations.

Benchmarking on IBM quantum devices confirmed that the developed algorithms outperform existing quantum approaches in terms of stability and accuracy. The project demonstrated that transcorrelated quantum chemistry methods could achieve results comparable to state-of-the-art classical methods while significantly reducing computational costs. These results provide a strong foundation for extending quantum simulations to larger, chemically relevant systems, a challenge that has so far been beyond the reach of current quantum computers.

To ensure further uptake and success, additional research is needed to refine these methods for larger molecular systems and explore hybrid approaches that combine quantum and classical computing. Further demonstration of these techniques on different quantum hardware platforms, including superconducting qubits and trapped-ion systems, will help validate their applicability and scalability.

Commercialization opportunities include integrating these algorithms into cloud-based quantum computing platforms, enabling researchers and industry professionals to access high-accuracy quantum chemistry tools. Collaboration with quantum hardware providers and software companies will be essential to drive adoption. Additionally, standardization efforts and regulatory support for quantum computing in scientific and industrial applications will help facilitate broader implementation.

By pushing the boundaries of quantum chemistry simulations, the QC-SQUARED project has paved the way for future breakthroughs in materials science, pharmaceuticals, and energy research. The continued development and international collaboration in this field will be crucial for realizing the full potential of quantum computing in solving real-world problems.