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arXiv 1206.4690cond-mat.str-el
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共线量子反铁磁体中带隙激发态的寿命

Lifetime of Gapped Excitations in a Collinear Quantum Antiferromagnet

A. L. Chernyshev, M. E. Zhitomirsky, N. Martin, L. -P. Regnault

摘要:

我们表明,磁耦合的局部调制有深远的影响的温度依赖性的光磁振子的弛豫速率在一个广泛的类的反铁磁体,其中间隙激发声自旋波共存。在具有易平面各向异性的二维共线反铁磁体中,带隙模的无序诱导弛豫速率Gamma_imp=Gamma_0+A(TlnT)^2大大超过了磁振子-磁振子阻尼Gamma_m-m= BT ^5,在低温下可以忽略不计。我们用高分辨中子共振自旋回波技术测量了XY反铁磁体BaNi_2(PO_4)_2中带隙磁振子的寿命,发现实验数据与理论预测非常吻合。同样强的影响,在三维的情况下,在非共线反铁磁体的障碍进行了讨论。

英文摘要:

We demonstrate that local modulations of magnetic couplings have a profound effect on the temperature dependence of the relaxation rate of optical magnons in a wide class of antiferromagnets in which gapped excitations coexist with acoustic spin waves. In a two-dimensional collinear antiferromagnet with an easy-plane anisotropy, the disorder-induced relaxation rate of the gapped mode, Gamma_imp=Gamma_0+A(TlnT)^2, greatly exceeds the magnon-magnon damping, Gamma_m-m=BT^5, negligible at low temperatures. We measure the lifetime of gapped magnons in a prototype XY antiferromagnet BaNi2(PO4)2 using a high-resolution neutron-resonance spin-echo technique and find experimental data in close accord with the theoretical prediction. Similarly strong effects of disorder in the three-dimensional case and in noncollinear antiferromagnets are discussed.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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