Articles and Theses – 2024

Marco Rossi

Epitaxy of Bottom-Up Grown InSb Nanostructures
PhD defense: 23 mei 2024, Eindhoven University of Technology, Eindhoven
Promoter: prof. dr. Erik Bakkers
Co-promoter: dr. Marcel A. Verheijen

Quantum computers are a revolutionary computing paradigm based on quantum mechanics. They use qubits, the quantum equivalent of bits, to potentially solve problems that classical computers cannot. Preserving the delicate quantum state of qubits is a challenge due to decoherence caused by interactions with the environment. Topological quantum computation offers a promising solution by utilizing Majorana zero modes (MZMs), which are quasiparticles excitations that are resistant to local sources of decoherence. This inherent robustness makes MZMs highly desirable for quantum information processing. Despite various theoretical proposals outlined the necessary conditions for achieving MZMs, experimental realization has yet to be achieved, leaving the existence of MZMs as an open question. The primary impediment to detecting MZMs currently stems from the level of disorder (e.g. crystal defects, impurities, surface roughness) present in the semiconductor-superconductor hybrid devices required for testing their existence. Furthermore, providing definitive proof necessitates the fabrication of a material platform wherein MZMs can be intricately braided within a complex network. These challenges require concerted material science efforts to provide such platform with minimal disorder. This thesis focuses on the bottom-up epitaxy of free-standing nanostructures made of indium antimonide (InSb), a promising semiconductor for constructing such devices due to its unique physical properties.