For the first time, scientists have been able to observe a quantum spin liquid in a laboratory.
The 'liquid' part refers to the electrons that are constantly changing inside a magnetic material. Unlike regular magnets, the electrons don't settle into the lattice of a solid as they are cooled.
The 'quantum spin' refers to the orientation of the angular momentum carried by particles, which are entangled in pairs with opposing spins. It's hoped that the discovery of the state will advance the development of quantum computers.
"This is a very special moment in the field of quantum physics," says Mikhail Lukin, a quantum physicist from Harvard University. It's a new state of matter that people have never been able to observe.
Magnets with electrons whose spin is in the same direction up or down are what generate magnetism.
The spin from the third electron throws out the balance in quantum spin liquids. The spins can't all be in one direction because it creates arustrated magnet.
The team used a quantum simulator to create their own lattice pattern. The simulation uses a quantum computer program to hold atoms in custom shapes using lasers, and can be used to engineer different quantum interactions and processes.
The researchers were able to create a frustrated magnet with properties of quantumentanglement by arranging the atoms of rubidium in a triangle-patterned lattice, and by using tightly focused laser beams to arrange atoms individually.
The connections between the atoms showed that a quantum spin liquid had been created.
"You can change the parameters of nature in a way that you couldn't in the material where these things were studied earlier," says quantum physicist Subir Sachdev, from Harvard.
You can look at each atom and see what it is doing.
It's hoped that quantum spin liquids will help in the development of qubits that are better protected against outside noise and interference.
That's important for a quantum computer. Getting these systems to work for extended periods of time without errors is one of the biggest challenges scientists are working on.
It should help in figuring out how to make qubits as robust as possible now that quantum spin liquids have been spotted for the first time. Researchers say there's a lot more to explore.
"Learning how to create and use such topological qubits would be a major step toward the realization of reliable quantum computers," says quantum physicist Giulia Semeghini from Harvard University.
The research has been published.
