Attractive Tomonaga-Luttinger liquid in a quantum spin ladder.
Attractive Tomonaga-Luttinger liquid in a quantum spin ladder.
复制标题
量子自旋梯中有吸引力的 Tomonaga-Luttinger 液体。
DOI：
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发表时间：
2013
影响因子：
8.6
通讯作者：
M. Horvatić
中科院分区：
文献类型：
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作者：
M. Jeong;H. Mayaffre;C. Berthier;D. Schmidiger;A. Zheludev;M. Horvatić
我们提出了一个强腿自旋1/2海森堡反铁磁梯形化合物（C7 H10 N）2CuBr 4在磁场高达15 T下的NMR测量温度范围从1.2 K下降到50 mK。从核磁共振谱线的分裂，我们确定了低温（三维）长程有序相的相边界和序参数。在有序相之上的Tomonaga-Luttinger区域，NMR弛豫反映了自旋相关函数的特征幂律衰减为1/T1 T（1/2K-1），这使得我们能够确定相互作用参数K作为场的函数。我们发现，依赖于场的K在1<K<2的范围内变化，这表明Tomonaga-Luttinger液体中无自旋费米子之间的吸引相互作用。
We present NMR measurements of a strong-leg spin-1/2 Heisenberg antiferromagnetic ladder compound (C7H10N)2CuBr4 under magnetic fields up to 15 T in the temperature range from 1.2 K down to 50 mK. From the splitting of NMR lines, we determine the phase boundary and the order parameter of the low-temperature (three-dimensional) long-range-ordered phase. In the Tomonaga-Luttinger regime above the ordered phase, NMR relaxation reflects characteristic power-law decay of spin correlation functions as 1/T1∝T(1/2K-1), which allows us to determine the interaction parameter K as a function of field. We find that field-dependent K varies within the 1<K<2 range, which signifies attractive interaction between the spinless fermions in the Tomonaga-Luttinger liquid.