A quantum state of matter has been made for the first time using 鈥渄ipolar鈥� molecules 鈥� molecules that have a positively charged end and a negatively charged end. It could help enhance our understanding of the quantum properties of exotic materials.
Historically, to understand the inner workings of a material, researchers might probe its atomic structure. But the complexity of those structures can make it difficult to figure out how the atoms interact and how the material behaves as a whole.
In recent years, a different approach has arisen that relies on experiments at extremely low temperatures. Materials are built one particle at a time to reveal how their arrangement and interactions the overall properties.
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at Columbia University in New York and his colleagues have now added new building blocks to this approach by creating a type of ultracold quantum matter called a Bose-Einstein condensate (BEC) using dipolar molecules 鈥� something that researchers have been attempting to do for almost decades without any success.
BECs are fluid-like and all the molecules within them have identical quantum states. This makes them a particularly promising starting point for creating and testing the quantum phenomena important for understanding materials.
To create their BEC, the researchers used dipolar molecules consisting of one sodium and one caesium atom. They hit them with electromagnetic forces from lasers and magnets as well as carefully tuned microwaves to radically reduce the temperature, ultimately reaching only several billionths of a degree above absolute zero.
The microwaves were crucial because they prevented molecules from getting too close together and warming up. The resulting BEC consisted of about 200 molecules.
鈥淭hese molecule experiments are incredibly challenging. The idea that you could actually get them this cold is something I was pessimistic about for a long time,鈥� says at Rice University in Texas.
He says the level of control needed over the molecules in the experiment could be used to create even more exotic quantum states of matter like counterintuitive solids that are also perfect fluids or other quantum materials that we do not fully understand.
鈥淔or almost 20 years theorists have produced predictions of what we might observe here. We鈥檒l see if we can reproduce them,鈥� says , also at Columbia University, who worked on the project. He is most excited about experiments where the team will put its molecules in arrangements so complicated that even the best computer simulations have failed to predict what new states of matter they will form next.
arXiv
