Quantum algorithms save time in calculating electron dynamics

Quantum algorithms save time in calculating electron dynamics

The calculations allow determination of electron density and post-excitation changes with high spatial and temporal resolution. Here, the example of a lithium hydride molecule shows the electron density shift from cyanide (red) to lithium (green) during a laser pulse. Credit: F. Langkabel/HZB

The researchers investigated the ability of known fault-tolerant quantum computing algorithms to simulate the laser-driven electron dynamics of excitation and ionization processes in small molecules. Their research has been published in Journal of Chemical Theory and Computation.

“This sleeve the computer Algorithms were originally developed in a completely different context. We used it here for the first time to calculate the electron density of particlesin particular its dynamic development after the thriller by A light pulse‘ says Anika Pandey, who heads the group Theoretical chemistry At the Helmholtz Association of German Research Centers (HZB). Pande and Fabian Langkapelle, who is doing her Ph.D. with her, show in the study how well this works.

“We developed an algorithm for a completely error-free phantom quantum computer and ran it on a classic server simulating a ten-qubit quantum computer,” says Langkabel. Scientists have limited their studies to smaller particles so that they can perform the calculations without a real quantum computer and compare them with conventional calculations.

Quantum algorithms produced the expected results. Unlike traditional accounts; However, quantum algorithms are also suitable for calculating significantly larger particles using quantum computers in the future.

“This has to do with the computation times. They increase with the number of atoms that make up the molecule,” says Langkabel. While computing time doubles with every added atom for traditional methods, this is not the case for Quantum algorithmswhich makes it much faster.

Photocatalysis, photoreception, and more

The study thus shows a new method for calculating electron densities and their ‘response’ to light excitation in advance, with spatial height and Temporal resolution. This makes it possible, for example, to simulate and understand ultrafast decay processes, which are also important in quantum computers made from so-called quantum dots.

In addition, it is possible to predict the physical or chemical behavior of molecules, for example during the absorption of light and the subsequent transfer of electric charges.

This could facilitate the development of photocatalysts to produce green hydrogen with sunlight or help to understand processes in the eye’s photosensitive receptor molecules.

more information:
Fabian Langkabel et al., Algorithm for quantitative computation of laser-driven microelectron dynamics in molecules, Journal of Chemical Theory and Computation (2022). DOI: 10.1021/acs.jctc.2c00878

the quote: Quantum Algorithms Save Time in Computing Electron Dynamics (2022, November 23) Retrieved November 23, 2022 from https://phys.org/news/2022-11-quantum-algorithms-electron-dynamics.html

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