In-gap spin excitations and finite triplet lifetimes in the dilute singlet ground state system SrCu2-xMgx(BO3)2

被引：22

作者：

Haravifard, S. ^{[1
]}

Dunsiger, S. R.

El Shawish, S.

Gaulin, B. D.

Dabkowska, H. A.

Telling, M. T. F.

Perring, T. G.

Bonca, J.

机构：

[1] McMaster Univ, Dept Phys & Astron, Hamilton, ON L8S 4M1, Canada

[2] Jozef Stefan Inst, SI-1000 Ljubljana, Slovenia

[3] Canadian Inst Adv Res, Toronto, ON M5G 1Z8, Canada

[4] Rutherford Appleton Lab, ISIS Pulsed Neutron Facil, Didcot OX11 0QX, Oxon, England

[5] Univ Ljubljana, Fac Math & Phys, SI-1000 Ljubljana, Slovenia

来源：

PHYSICAL REVIEW LETTERS | 2006年 / 97卷 / 24期

关键词：

D O I：

10.1103/PhysRevLett.97.247206

中图分类号：

O4 [物理学];

学科分类号：

0702 ;

摘要：

High resolution neutron scattering measurements on a single crystal of SrCu2-xMgx(BO3)(2) with x similar to 0.05 reveal the presence of new spin excitations within the gap of this quasi-two-dimensional, singlet ground state system. The application of a magnetic field induces Zeeman-split states associated with S=1/2 unpaired spins which are antiferromagnetically correlated with the bulk singlet. Substantial broadening of both the one- and two-triplet excitations in the doped single crystal is observed, as compared with pure SrCu2(BO3)(2). Theoretical calculations using a variational algorithm and a single quenched magnetic vacancy on an infinite lattice are shown to qualitatively account for these effects.

引用

页数：4

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