Quantum spin liquids could enable next-generation Quantum Computing

Schematization of crystal structure and the Kitaev basis of CrSiTe 3 monolayer. The black parallelogram marks the unit cell of the honeycomb lattice of CrSiTe 3 monolayer. The { X Y Z } basis of the Kitaev model is indicated by red, green, and blue arrows, which is determined by Löwdin orthogonalization [17] of the hard axes of the nearest neighbor Cr-Cr interactions. The X , Y , and Z directions are found to be very close to the Cr ─ Te bonds

A recent discovery by University of Arkansas physicists could help researchers establish the existence of quantum spin liquids, a new state of matter. They’ve been a mystery since they were first proposed in the 1970s. If proven to exist, quantum spin liquids would be a step toward much faster, next-generation quantum computing.

Scientists have focused attention and research on the so-called Kitaev-type of spin liquid, named in honor of the Russian scientist, Alexei Kitaev, who first proposed it. In particular, they have looked extensively at two materials – RuCl3  and Na2IrO – as candidates for this type. Both have small quantum spin numbers.

In their recent work, U of A physicists have greatly expanded the number of materials that might be candidates as Kitaev quantum spin liquids by looking at materials with higher quantum spin numbers, and by putting materials under physical strain to tune their magnetic states.

Quantum spin liquids are defined by their unusual magnetic arrangement. Magnets have a north and south pole, which combined are called dipoles. These are typically produced by the quantum spin of electrons. Inside a magnetic material, dipoles tend to all be parallel to each other (ferromagnetism) or periodically alternate their up and down direction (antiferromagnetism). 

In the case of hypothetical quantum spin liquids, dipoles aren’t as well ordered. Instead, they exhibit unusual ordering within a small distance of each other. Different ordering creates different types of spin liquids.

The team used computational models to predict a Kitaev quantum spin liquid state in materials such as chromium iodide and chromium germanium telluride. (SciTechDaily)

The paper has been published in Physical Review Letters.

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