Publications by authors named "E M Hankiewicz"
Article Synopsis
- The text discusses how magnetic impurities on superconducting surfaces create resonances called YSR states, which are linked to the behavior of superconducting pairs.
- These resonances exhibit a periodic pattern around impurities but often have wavelengths too short to be detected with standard techniques like scanning tunneling microscopy (STM).
- The authors improve imaging by using a CO molecule with a superconducting cluster on an STM tip, allowing for the visualization of complex interference patterns from YSR states that were previously undetectable, enhancing our understanding of superconductivity at the atomic level.
Article Synopsis
- The paper discusses how the band inversion in 3D topological materials connects to the parity anomaly seen in 2D massless Dirac fermions.
- It presents findings from experiments on the topological insulator (Hg,Mn)Te, highlighting a specific behavior in the quantized Hall resistance that ties back to spectral asymmetry.
- The observed phenomenon may occur in other topological insulators where a single Dirac surface state governs transport.
The scientific interest in two-dimensional topological insulators (2D TIs) is currently shifting from a more fundamental perspective to the exploration and design of novel functionalities. Key concepts for the use of 2D TIs in spintronics are based on the topological protection and spin-momentum locking of their helical edge states. In this study we present experimental evidence that topological protection can be (partially) lifted by pairwise coupling of 2D TI edges in close proximity.
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- The study explores how quantum spin Hall edge channels behave under strong magnetic fields, revealing that the expected transport gap does not appear in disordered topological insulators.
- Instead, researchers find that a topological edge channel exists alongside a counterpropagating quantum Hall edge channel even in strong fields.
- By adjusting disorder from fabrication methods, the research suggests that the observed quantum Hall edge channels are linked to a network of charge puddles at the device's edges.
The realization of the quantum spin Hall effect in HgTe quantum wells has led to the development of topological materials, which, in combination with magnetism and superconductivity, are predicted to host chiral Majorana fermions. However, the large magnetization in conventional quantum anomalous Hall systems makes it challenging to induce superconductivity. Here, we report two different emergent quantum Hall effects in (Hg,Mn)Te quantum wells.
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