Quantum spin liquid represents an intriguing state where electron spins are highly entangled yet spin fluctuation persists even at 0 K.Recently,the hexaaluminates RMgAl_(11)O_(19)(R=rare earth)have been proposed to be...Quantum spin liquid represents an intriguing state where electron spins are highly entangled yet spin fluctuation persists even at 0 K.Recently,the hexaaluminates RMgAl_(11)O_(19)(R=rare earth)have been proposed to be a platform for realizing the quantum spin liquid state with dominant Ising anisotropic correlations.Here,we report detailed low-temperature magnetic susceptibility,muon spin relaxation,and thermodynamic studies on the CeMgAl_(11)O_(19) single crystal.Ising anisotropy is revealed by magnetic susceptibility measurements.Muon spin relaxation and ac susceptibility measurements rule out any long-range magnetic ordering or spin freezing down to 50 mK despite the onset of spin correlations below∼0.8 K.Instead,the spins keep fluctuating at a rate of 1.0(2)MHz at 50 mK.Specific heat results indicate a gapless excitation with a power-law dependence on temperature,C_(m)(T)∝Tα.The quasi-quadratic temperature dependence withα=2.28(4)in zero field and linear temperature dependence in 0.25 T support the possible realization of the U(1)Dirac quantum spin liquid state.展开更多
基金supported by the Guangdong Basic and Applied Basic Research Foundation (Grant No.2022B1515120020)the National Natural Science Foundation of China (Grant No.11874158)The μSR experiments were supported by MLF of J-PARC under a user program (Grant No.2023B0022)
文摘Quantum spin liquid represents an intriguing state where electron spins are highly entangled yet spin fluctuation persists even at 0 K.Recently,the hexaaluminates RMgAl_(11)O_(19)(R=rare earth)have been proposed to be a platform for realizing the quantum spin liquid state with dominant Ising anisotropic correlations.Here,we report detailed low-temperature magnetic susceptibility,muon spin relaxation,and thermodynamic studies on the CeMgAl_(11)O_(19) single crystal.Ising anisotropy is revealed by magnetic susceptibility measurements.Muon spin relaxation and ac susceptibility measurements rule out any long-range magnetic ordering or spin freezing down to 50 mK despite the onset of spin correlations below∼0.8 K.Instead,the spins keep fluctuating at a rate of 1.0(2)MHz at 50 mK.Specific heat results indicate a gapless excitation with a power-law dependence on temperature,C_(m)(T)∝Tα.The quasi-quadratic temperature dependence withα=2.28(4)in zero field and linear temperature dependence in 0.25 T support the possible realization of the U(1)Dirac quantum spin liquid state.
