Quantum criticality of the Ising-like screw chain antiferromagnet SrCo2V2O8 in a transverse magnetic field

Y. Cui; H. Zou; N. Xi; Zhangzhen He; Y. X. Yang; L. Shu; G. H. Zhang; Z. Hu; T. Chen; Rong Yu; Jianda Wu; Weiqiang Yu

doi:10.1103/PhysRevLett.123.067203

paper

Quantum criticality of the Ising-like screw chain antiferromagnet SrCo2V2O8 in a transverse magnetic field

arXiv:1904.11413 · doi:10.1103/PhysRevLett.123.067203

Abstract

The quantum criticality of an Ising-like screw chain antiferromagnet SrCo $_{2}$ V $_{2}$ O $_{8}$ , with a transverse magnetic field applied along the crystalline $a$ -axis, is investigated by ultra-low temperature NMR measurements. The NÃ©el temperature is rapidly and continuously suppressed by the field, giving rise to a quantum critical point (QCP) at $H_{C_{1}}$ $\approx$ ~7.0~T. Surprisingly, a second QCP at $H_{C_{2}} \approx$ ~7.7~T featured with gapless excitations is resolved from both the double-peak structure of the field dependent spin-lattice relaxation rate $1 /^{51} T_{1}$ at low temperatures and the weakly temperature-dependent $1 /^{51} T_{1}$ at this field. Our data, combined with numerical calculations, suggest that the induced effective staggered transverse field significantly lowers the critical fields, and leads to an exposed QCP at $H_{C_{2}}$ , which belongs to the one-dimensional transverse-field Ising universality.

4 figure, 1 supplemental materials upon request