Disorder upon disorder: Localization effects in the Kitaev spin liquid

Disorder, Low-Energy Excitations, and Topology in the Kitaev Spin Liquid

“…After the H 3 LiIr 2 O 6 results came out, some attempts were made in order to explain its phenomenology 41,42,92,93 and current consensus is that structural disorder plays an important role in this compound, such as stacking faults, 1,93 and the random position of the H atoms. 94 Therefore, a minimal model should consider both the effects of non-Kitaev interactions and structural defects, as we present in the following sections.…”

Disorder effects in the Kitaev-Heisenberg model

“…In addition, presence of disorder like vacancies, impurities, lattice distortions, and stacking faults, inevitable in real materials, are often responsible for the instability of QSL [12][13][14]. Recently, a new class of intercalated compounds have been synthesized which are even more susceptible to disorder H 3 LiIr 2 O 6 , Cu 2 IrO 3 , and Ag 3 LiIr 2 O 6 [15,16].…”

Disorder, low-energy excitations, and topology in the Kitaev spin-liquid

“…Moreover, as reported in the previous section, strong disorder in the Kitaev model may also affect the flux state, making this asymptotic scenario not too relevant for our analysis. The problem of bond disorder in the Kitaev honeycomb model has already been addressed in previous numerical studies, 41,92 where the divergence in the low energy DOS was identified as a power-law distribution, in accordance with the H 3 LiIr 2 O 6 phenomenology. Here, we report the same qualitative behavior for the pure Kitaev model, and further extend the analysis by considering the extended model in Eq.…”

“…For K 3 = κ = 0, both the 0-flux and random-flux states produce the desired diverging power-law behavior at low-E: ρ (E) ∼ E −α , in agreement with the results of Refs. 41,92 First, we shall notice that if one assumes that the flux degrees of freedom are frozen, it follows that C/T ∼ T −α , 41,42 as observed in H 3 LiIr 2 O 6 . 1 Furthermore, we point out that a pile-up of low energy states is only seen for the 0-flux configuration in the strong disorder regime presented in Fig.…”

“…After the H 3 LiIr 2 O 6 results came out, some attempts were made in order to explain its phenomenology 41,42,92,93 and current consensus is that structural disorder plays an important role in this compound, such as stacking faults, 1,93 and the random position of the H atoms. 94 Therefore, a minimal model should consider both the effects of non-Kitaev interactions and structural defects, as we present in the following sections.…”