Magnetic materials believed to host a quantum spin liquid have drawn strong interest because of their potential to reveal exotic states of matter and advance quantum computing. However, appearances in the quantum world can be misleading. A new study published in Science Advances and co-led by Rice University's Pengcheng Dai shows that cerium magnesium hexalluminate (CeMgAl 11 O 19 ), once thought to belong to this rare category, is not actually a quantum spin liquid. "The material had been classified as a quantum spin liquid due to two properties: observation of a continuum of states and lack of magnetic ordering," said Bin Gao, co-first author and a research scientist at Rice. "But closer observation of the material showed that the underlying cause of these observations wasn't a quantum spin liquid phase." How Magnetic States Normally Behave In insulating materials such as CeMgAl 11 O 19 , magnetic ions like cerium can adopt one of two arrangements: ferromagnetic or anti-ferromagnetic.…