论文标题
量子旋转液体候选ETME $ _3 $ sb [pd（dmit）$ _ 2 $] $ _ 2 $
Presence and absence of itinerant gapless excitations in the quantum spin liquid candidate EtMe$_3$Sb[Pd(dmit)$_2$]$_2$
论文作者
论文摘要
ETME $ _3 $ SB [PD（DMIT）$ _ 2 $] $ _ 2 $，一种有机Mott绝缘子，具有几乎各向同性三角形晶格，是量子旋转液体的候选材料，其中零点波动不允许旋转订购。该系统中的热运输测量结果推断出的巡回无间隙激发已成为一个激烈的辩论问题。虽然存在有限的线性残留导热率，但已显示$κ____________ERIVκ/t（T \ rightarrow 0）$ [M. Yamashita {\ it等} Science {\ BF 328}，1246（2010）]，最近的实验[P. Bourgeois-Hope {\ it等人}，Phys。修订版X {\ bf 9}，041051（2019）; J. M. Ni {\ it等人}，物理。莱特牧师。 {\ bf 123}，247204（2019）]报告说缺少$κ_0/t $。在这里，我们表明，低温导热率在很大程度上取决于样品的冷却过程。冷却非常缓慢时，会观察到相当大的$κ__0/t $。相比之下，当快速冷却时，$κ_0/t $消失，此外，声子导电率也会被强烈抑制。这些结果表明，在冷却过程中引入的可能的随机散射器是导致该有机系统中热导率数据的明显差异。目前的结果提供了证据，表明ETME $ _3 $ SB [PD（DMIT）$ _ 2 $] $ _ 2 $的真实基态可能是带有流动无间隙激发的量子旋转液体。
EtMe$_3$Sb[Pd(dmit)$_2$]$_2$, an organic Mott insulator with nearly isotropic triangular lattice, is a candidate material for a quantum spin liquid, in which the zero-point fluctuations do not allow the spins to order. The itinerant gapless excitations inferred from the thermal transport measurements in this system have been a hotly debated issue recently. While the presence of a finite linear residual thermal conductivity, $κ_0/T \equiv κ/T (T \rightarrow 0)$, has been shown [M. Yamashita {\it et al.} Science {\bf 328}, 1246 (2010)], recent experiments [P. Bourgeois-Hope {\it et al.}, Phys. Rev. X {\bf 9}, 041051 (2019); J. M. Ni {\it et al.}, Phys. Rev. Lett. {\bf 123}, 247204 (2019)] have reported the absence of $κ_0/T$. Here we show that the low-temperature thermal conductivity strongly depends on the cooling process of the sample. When cooling down very slowly, a sizable $κ_0/T$ is observed. In contrast, when cooling down rapidly, $κ_0/T$ vanishes and, in addition, the phonon thermal conductivity is strongly suppressed. These results suggest that possible random scatterers introduced during the cooling process are responsible for the apparent discrepancy of the thermal conductivity data in this organic system. The present results provide evidence that the true ground state of EtMe$_3$Sb[Pd(dmit)$_2$]$_2$ is likely to be a quantum spin liquid with itinerant gapless excitations.
