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arXiv · 1904.11413

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
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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 N\'{e}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.

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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. 2019-04-25. Quantum criticality of the Ising-like screw chain antiferromagnet SrCo2V2O8 in a transverse magnetic field. https://doi.org/10.1103/physrevlett.123.067203

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