Researchers at the University of Queensland (UQ) have produced what may very well be the first pieces of art made using non-classical matter. The team has reproduced famous artworks like the Mona Lisa and Starry Night on a "quantum canvas" as small as a human hair, by projecting light onto Bose-Einstein condensates (BECs).
BECs are an exotic state of matter known as a superfluid, meaning it's a liquid that has zero viscosity so it flows without resistance. They're most commonly made by cooling a cloud of rubidium atoms down to almost the coldest temperature possible – a few billionths of a degree above absolute zero. At that intense temperature, the atoms slow down almost to a standstill, and essentially begin acting like one big atom.
That makes quantum behavior visible on a large scale. Recent experiments have used BECs as a starting point to create unusual forms of matter such as supersolids, excitonium, "giant atoms" with other atoms inside them, and fluids exhibiting negative mass.
For the new study, the UQ researchers explored the more artistic side of this strange stuff. They used the BEC as a kind of quantum canvas, reproducing images such as the Mona Lisa, Van Gogh's Starry Night, and photos of the researchers themselves. These images were projected backwards through a microscope so they came out tiny – only 100 microns wide, which is roughly the width of a human hair. Each pixel is composed of only about 50 atoms.
But it's not just a matter of using the BEC as a surface to project images onto, like you might do to create holograms on mist. The researchers are actually making use of the substance's spooky quantum properties to make the art.
One of the quirks of quantum physics is that in a system such as a BEC, the atoms don't have set positions until they're measured – before then, they're said to be distributed within the system. The most famous example of course is that of Schrödinger's Cat: a cat in a box with flask of poison and a radioactive "trigger" could be considered neither alive nor dead, but both at the same time. When you try to measure it (say by peeking into the box), the wave function of possibilities collapses into one state or the other.
In the same way, the atoms inside the BEC are kind of everywhere at once, and only collapse into a set position once they're measured. In this case, that measurement involves shining the projected light onto the stuff. The light pushes the atoms around – in effect confirming that they're not where the light is – which concentrates the atoms inside the darker areas of the image.
"The BEC state is destroyed by illuminating it with light, collapsing the quantum state with the act of measurement," Tyler Neely, lead researcher on the study, tells New Atlas. "The images shown do represent the density of the atoms, and I can consider each atom in the image to have a position within the accuracy of my measurement, behaving like a classical particle. However, prior to me taking the image, it is incorrect to think about each atom having a position, instead that it was distributed in the system."
The images themselves are only black-and-white, but the team can add color by performing the experiment three times over with red, green and blue filters. These are then combined on a computer to create an approximate color image.
Collapsing wave functions to produce images makes this a very strange new artistic medium – Schrödinger's Art, you might call it. The team is now looking to start collaborating with artists to help the concept reach its creative potential.
"I find the intersection between art and science fascinating," Neely tells us. "Part of this interplay is that science can provide new materials for artists to work with. I believe Bose-Einstein condensates represent such a new material. In contrast to all other artistic materials, BECs are not governed by classical physics, but instead realize macroscopic quantum mechanical states. Since a BEC can be described as a giant matter-wave, these artworks represent the first time non-classical matter has been used to produce such detailed pictures."
Source: University of Queensland