Quantum Spin Hall insulators are particularly attractive materials due to theintrinsic appearance of robust conducting surface states. They represent anew quantum state of matter and offer the...Show moreQuantum Spin Hall insulators are particularly attractive materials due to theintrinsic appearance of robust conducting surface states. They represent anew quantum state of matter and offer the potential of realizing dissipationa-less spin current devices, making them appealing from both a fundamentaland applied point of view. In realistic devices, multiple such states co-existat the surface, but only one pair can be considered ‘topologically’ protectedfrom back-scattering. Thus, the desired robust pair is buried under ‘triv-ial’ conductance. Would the presence of disorder suppress the conductanceof the trivial states, enabling us to capture the topological states? In thisthesis, using a first-principles derived model, we study the effect of disorderon the electronic transport of nanoribbons. Our results show that trivialconductance vanishes for strong enough disorder, and topological protectionsurvives even when a disorder-induced band gap closing occursShow less
