We have analyzed the breakdown of the quantum Hall effect in 1 mu m wide Hall devices fabricated from an exfoliated monolayer graphene transferred on SiOx. We have observed that the deviation of the Hall resistance from its quantized value is weakly dependent on the longitudinal resistivity up to a current density of 5 A/m, where the Hall resistance remains quantized even when the longitudinal resistance increases monotonously with the current. Then a collapse in the quantized resistance occurs while longitudinal resistance keeps its gradual increase. The exponential increase of the conductivity with respect to the current suggests impurity mediated inter-Landau level scattering as the mechanism of the breakdown. The results are interpreted as the strong variation of the breakdown behavior throughout the sample due to the randomly distributed scattering centers that mediates the breakdown.
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机译：我们已经分析了由剥离的单层石墨烯转移到SiOx上制成的1微米宽霍尔器件中的量子霍尔效应的分解。我们已经观察到，霍尔电阻与其量化值的偏差在很大程度上取决于纵向电阻率，直到电流密度为5 A / m，即使纵向电阻随电流单调增加，霍尔电阻仍保持量化。然后，在纵向电阻保持其逐渐增加的同时，发生了量化电阻的崩溃。电导率相对于电流的指数增长表明，杂质介导的兰道间能级散射是击穿的机理。结果被解释为由于介导击穿的随机分布的散射中心，整个样品击穿行为的强烈变化。
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