In recent years, several magnetic Mott insulators with strong spin–orbit couplings were suggested to be proximate to the Kitaev quantum spin liquid (QSL) whose one of the most exciting features is the fractionalization of spin excitations into itinerant Majorana fermions and static $Z_2$ fluxes. Motivated by the emergence of this plethora of 4d and 5d transition metal Kitaev materials and by the fact that some level of disorder is inevitable in real materials, here we study how the Kitaev QSL responds to various forms of disorder, such as vacancies, impurities, and bond randomness. First, we argue that the presence of the quenched disorder in the Kitaev QSL can lead to the Anderson localization of Majorana fermions and the appearance of Lifshitz tails. We point out that the Anderson localization of low-energy states is particularly strong in the extended Kitaev model with the time reversal symmetry breaking term. Second, we show that the disorder effects on the low-energy Majorana fermion modes can be detected in thermal transport. Third, we show that at finite temperatures the $Z_2$ fluxes become thermally excited and give rise to an additional disorder for the Majorana fermions. This source of the disorder dominates at high temperatures. Fourth, we demonstrate that both the structure of the energy spectrum and the thermal transport properties of the disordered Kitaev QSL depend strongly on the character of disorder. While we find that both the site disorder and the bond randomness suppress the longitudinal thermal conductivity, the low-energy localization is stronger in the case of the site disorder.

近年来，一些具有强自旋轨道耦合的磁性Mott绝缘子被认为最接近Kitaev量子自旋液体（QSL），其最令人兴奋的特征之一是将自旋激发分为多个流动的马里亚纳费米子和静电子。 ${ž}_{\mathrm{2个}}$通量。受到大量4d和5d过渡金属Kitaev材料的出现以及在实际材料中不可避免地存在一定程度的无序这一事实的激励，在这里，我们研究Kitaev QSL如何响应各种形式的无序，例如空位，杂质，和键的随机性。首先，我们认为Kitaev QSL中淬灭性障碍的存在可能导致Majorana费米子的Anderson局部化和Lifshitz尾巴的出现。我们指出，在具有时间反转对称破坏项的扩展Kitaev模型中，低能态的Anderson局域化特别强。其次，我们表明可以在热传输中检测到对低能马约拉那费米子模式的无序影响。第三，我们证明了在有限的温度下${ž}_{\mathrm{2个}}$通量变得热激发，并引起马约拉那费米子的其他混乱。这种疾病的根源在高温下占主导地位。第四，我们证明了无序的Kitaev QSL的能谱结构和热传输特性都强烈依赖于无序的特性。虽然我们发现位点紊乱和键的无规性都抑制了纵向热导率，但在位点紊乱的情况下，低能定位更强。