Seminar: Dr. Katharina Laubscher | UMD
In-Person PHYS 401
Location
Physics : 401
Date & Time
October 15, 2025, 11:00 am – 12:00 pm
Description
TITLE: "Majorana zero modes in germanium-based semiconductor-superconductor hybrid devices”
ABSTRACT: Majorana zero modes are exotic non-Abelian quasiparticles that are of great interest as potential building blocks for fault-tolerant quantum computing. However, despite intense experimental efforts, their unambiguous detection remains challenging due to the presence of substantial disorder in existing InAs-based devices. In this talk, I will discuss germanium hole nanowires as an alternative platform for the realization of Majorana zero modes, presenting theoretical phase diagrams, estimates of the topological gap, and simulated conductance maps. While the topological gaps are generally smaller than in InAs-based devices, the superior material quality of Ge strongly suppresses disorder-induced Andreev bound states and the resulting spurious conductance signals, thereby reducing ambiguities in the interpretation of transport data. If time permits, I will also touch on planar Josephson junctions based on two-dimensional Ge hole gases as another route towards Ge-based Majorana zero modes.
ABSTRACT: Majorana zero modes are exotic non-Abelian quasiparticles that are of great interest as potential building blocks for fault-tolerant quantum computing. However, despite intense experimental efforts, their unambiguous detection remains challenging due to the presence of substantial disorder in existing InAs-based devices. In this talk, I will discuss germanium hole nanowires as an alternative platform for the realization of Majorana zero modes, presenting theoretical phase diagrams, estimates of the topological gap, and simulated conductance maps. While the topological gaps are generally smaller than in InAs-based devices, the superior material quality of Ge strongly suppresses disorder-induced Andreev bound states and the resulting spurious conductance signals, thereby reducing ambiguities in the interpretation of transport data. If time permits, I will also touch on planar Josephson junctions based on two-dimensional Ge hole gases as another route towards Ge-based Majorana zero modes.
