Spin excitations and quantum criticality in the quasi-one-dimensional Ising-like ferromagnet CoCl2 • 2D2O in a transverse field

被引：6

作者：

Larsen, J. ^{[1
]}

Schaffer, T. K. ^{[2
]}

Hansen, U. B. ^{[2
]}

Holm, S. L. ^{[2
]}

Ahl, S. R. ^{[1
,2
]}

Toft-Petersen, R. ^{[1
,3
]}

Taylor, J. ^{[4
]}

Ehlers, G. ^{[5
]}

Jensen, J. ^{[6
]}

Ronnow, H. M. ^{[7
]}

Lefmann, K. ^{[2
]}

Christensen, N. B. ^{[1
,8
]}

机构：

[1] Tech Univ Denmark, Dept Phys, DK-2800 Lyngby, Denmark

[2] Niels Bohr Inst, Nanosci Ctr, Univ Pk 5, DK-2100 Copenhagen O, Denmark

[3] Helmholtz Ctr Energy & Mat, D-14109 Berlin, Germany

[4] European Spallat Source ERIC, Data Management & Software Ctr, Ole Maaloes Vej 3, DK-2200 Copenhagen N, Denmark

[5] Oak Ridge Natl Lab, Quantum Condensed Matter Div, Oak Ridge, TN 37830 USA

[6] Niels Bohr Inst, Univ Pk 5, DK-2100 Copenhagen O, Denmark

[7] Ecole Polytech Fed Lausanne, Inst Phys, Lab Quantum Magnetism, CH-1015 Lausanne, Switzerland

[8] Paul Scherrer Inst, Lab Neutron Scattering & Imaging, CH-5232 Villigen, Switzerland

来源：

PHYSICAL REVIEW B | 2017年 / 96卷 / 17期

关键词：

MAGNETIC-STRUCTURE; PHASE-TRANSITION; ANTIFERROMAGNETISM; SUSCEPTIBILITY; RESONANCE;

D O I：

10.1103/PhysRevB.96.174424

中图分类号：

T [工业技术];

学科分类号：

08 ;

摘要：

We present experimental evidence for a quantum phase transition in the easy-axis S = 3/2 anisotropic quasi-one-dimensional ferromagnet CoCl2 center dot 2D(2)O in a transverse field. Elastic neutron scattering shows that the magnetic order parameter vanishes at a transverse critical field mu H-0(c) = 16.05(4) T, while inelastic neutron scattering shows that the gap in the magnetic excitation spectrum vanishes at the same field value, and reopens forH > H-c. The field dependence of the order parameter and the gap are well described by critical exponents beta = 0.45 +/- 0.09 and z.nu close to 1/2, implying that the quantum phase transition in CoCl2 center dot 2D(2)O differs significantly from the textbook version of a S = 1/2 Ising chain in a transverse field. We attribute the difference to weak but finite three-dimensionality of the magnetic interactions.

引用

页数：6

共 27 条

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