Spin-liquid state in a geometrically frustrated antiferromagnet CrMgGaO4

Quenched randomness offered a novel paradigm in stabilizing quantum disordered spin-liquid-like states in geometrically frustrated magnets. This notion is exemplified in a range of quantum magnets. This naturally gives rise to a hierarchy of magnetism: quantum paramagnet at high T and random quantum disordered magnet at low T. As bond randomness generates abundant low-energy excitations that mimic a gapless quantum spin liquid, spin excitations and dynamics will be distinct from what is expected for the true quantum spin liquid. Here, we introduce a new frustrated antiferromagnet CrMgGaO4, wherein Cr3+ (S = 3/2) ions are connected to each other via a corner-shared tetrahedral network in 3D. The proposed study will deepen our understanding of the role of chemical disorders in modifying low-energy spin excitations on a microscopic scale in frustrated 3D antiferromagnets.