Is Y(Sc)Mn2 really a quantum spin liquid

Abstract Spin fluctuations in frustrated Y 0.97 Sc 0.03 Mn 2 have been studied by μ + SR. The relaxation rate increases monotonically with decreasing temperature and is not appreciably changed by the longitudinal field, in contrast with that in Y 0.97 Sc 0.03 (Mn 0.9 Al 0.1 ) 2 . These results imply fluctuations in a quantum spin liquid.