Intact quasiparticles at an unconventional quantum critical point
Intact quasiparticles at an unconventional quantum critical point
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DOI：
10.1103/physrevb.92.041114
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发表时间：
2014-07
影响因子：
3.7
通讯作者：
Mike Sutherland;E. O’Farrell;W. Toews;J. Dunn;K. Kuga;S. Nakatsuji;Y. Machida;Koichi Izawa;R. W. Hill
中科院分区：
文献类型：
--
作者：
Mike Sutherland;E. O’Farrell;W. Toews;J. Dunn;K. Kuga;S. Nakatsuji;Y. Machida;Koichi Izawa;R. W. Hill
本文报道了重费米子金属β-YbAlB 4在非常规量子临界点附近的T → 0极限下的面内电输运和热输运性质的测量结果。在这种材料中，近藤温度高达TK-200 K，这使得我们能够在T/T K < 5 × 10 −4的异常小的值下探测非常接近临界点的输运。在这里，我们发现，在最低温度下遵守Wiedemann-Franz定律，这意味着朗道准粒子保持完整的临界区域。在有限的温度下，我们观察到一个非费米液体T -线性依赖的非弹性散射过程的能量低于以前访问。这些过程的温度依赖性比类似的重费米子量子临界系统要弱，揭示了T = 0.3 K的温度尺度，这表明非弹性散射的性质发生了突然变化。
We report measurements of in-plane electrical and thermal transport properties in the limit T → 0 near the unconventional quantum critical point in the heavy-fermion metal β-YbAlB4. The high Kondo temperature TK � 200 K in this material allows us to probe transport extremely close to the critical point, at unusually small values of T/T K < 5 × 10 −4 . Here we find that the Wiedemann-Franz law is obeyed at the lowest temperatures, implying that the Landau quasiparticles remain intact in the critical region. At finite temperatures we observe a non-Fermi-liquid T -linear dependence of inelastic-scattering processes to energies lower than those previously accessed. These processes have a weaker temperature dependence than in comparable heavy fermion quantum critical systems, revealing a temperature scale of T ∼ 0.3 K which signals a sudden change in the character of the inelastic scattering.