Ivan Kassal, University of Sydney and Tingrei Tan, University of SydneyWhen a molecule absorbs light, it undergoes a whirlwind of quantum-mechanical transformations. Electrons jump between energy levels, atoms vibrate, and chemical bonds shift — all within millionths of a billionth of a second.
These processes underpin everything from photosynthesis in plants and DNA damage from sunlight, to the operation of solar cells and light-powered cancer therapies.
Yet despite their importance, chemical processes driven by light are difficult to simulate accurately. Traditional computers struggle, because it takes vast computational power to simulate this quantum behaviour.
Quantum computers, by contrast, are themselves quantum systems — so quantum behaviour comes naturally. This makes quantum computers natural candidates for simulating chemistry.
Until now, quantum devices have only been able to calculate unchanging things, such as the energies of molecules. Our study, published this week in the Journal of the American Chemical Society, demonstrates we can also model how those molecules change over time.
We experimentally simulated how specific real molecules behave after absorbing light.
Simulating reality with a single ion
We used what is called a trapped-ion quantum computer. This works by manipulating individual atoms in a vacuum...
