论文标题
基塔夫材料中的分数化抗铁磁和野外诱导状态的热传输
Thermal Transport of Fractionalized Antiferromagnetic and Field Induced States in the Kitaev Material Na$_2$Co$_2$TeO$_6$
论文作者
论文摘要
我们报告了一项honeycomb kitaev材料NA $ _2 $ CO $ _2 $ _2 $ teo $ _6 $的平面内热运输研究。在零字段中，$κ（t）$显示出相当弱的$ t $依赖性，但具有非零的残留项$κ__0/t $，表明通过磁激发来强烈的声子散射，并且静脉刺激的可能性与静脉相关的静态序列相同。磁性和分数激发。沿着$ a*$（共核算键）方向的热电流和外部场，$κ_{a*} $在7.5 t和10 t时表现出两个尖锐的最小值，其值为8.5 t的值与高田极化状态的纯语音传输几乎相同。这证实了所报道的现场诱导的中间状态的相边界，并表明其无间隙连续性激发可能传输热量。沿$κ_A$在$ $ $（Zigzag链）方向的$κ_A$中没有发现此类中间阶段。最后，na $ _2 $ co $ _2 $ teo $ _6 $显示出强烈的各向异性磁电磁电导率，因为平面（平面外）字段强烈增强（抑制）$κ___{a*} $ and $κ_A__A$。
We report an in-plane thermal transport study of the honeycomb Kitaev material Na$_2$Co$_2$TeO$_6$ at subKelvin temperatures. In zero field, the $κ(T)$ displays a rather weak $T$-dependence but has a non-zero residual term $κ_0/T$, indicating strong phonon scattering by magnetic excitation and the possibility of itinerant spinon-like excitations coexisting with an antiferromagnetic order below 27 K. We propose the zero-field ground state is a novel fractionalized antiferromagnetic (AF*) state with both magnetic order and fractionalized excitations. With both the heat current and external field along the $a*$ (Co-Co bond) direction, the $κ_{a*}$ exhibits two sharp minima at 7.5 T and 10 T, and its value at 8.5 T is almost the same as the pure phononic transport for the high-field polarized state. This confirms the phase boundaries of the reported field-induced intermediate state and suggest its gapless continuum excitations possibly transport heat. No such intermediate phase was found in the $κ_a$ for the current and field along the $a$ (zigzag chain) direction. Finally, Na$_2$Co$_2$TeO$_6$ displays a strongly anisotropic magneto-thermal conductivity since the in-plane (out-of-plane) field strongly enhances (suppresses) the $κ_{a*}$ and $κ_a$.
