Disorder is generally thought to be detrimental to creating materials with unusual magnetism or other quantum phenomena. However, a team found that weak disorder surprisingly stabilizes a rare quantum state called a quantum spin liquid. In this state, fluctuations of electronic spins persist all the way to temperatures near absolute zero. The particular material is made of praseodymium, zirconium, and oxygen (Pr2Zr2O7). The material contains rare earth ions (Pr3+) with an even number of electrons on a weakly disordered crystalline lattice. While the crystalline lattice frustrates conventional magnetism, weak disorder promotes the rare quantum spin liquid state.