Publications by authors named "D K Morr"

Realizing hybrids of low-dimensional Kondo lattices and superconducting substrates leads to fascinating platforms for studying the exciting physics of strongly correlated electron systems with induced superconducting pairing. Here, we report a scanning tunneling microscopy and spectroscopy study of a new type of two-dimensional (2D) La-Ce alloy grown epitaxially on a superconducting Re(0001) substrate. We observe the characteristic spectroscopic signature of a hybridization gap evidencing the coherent spin screening in the 2D Kondo lattice realized by the ultrathin La-Ce alloy film on normal conducting Re(0001).

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Qubits built out of Majorana zero modes constitute the primary path toward topologically protected quantum computing. Simulating the braiding process of multiple Majorana zero modes corresponds to the quantum dynamics of a superconducting many-body system. It is crucial to study the Majorana dynamics both in the presence of all other quasiparticles and for reasonably large system sizes.

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A Kondo lattice is often electrically insulating at low temperatures. However, several recent experiments have detected signatures of bulk metallicity within this Kondo insulating phase. In this study, we visualized the real-space charge landscape within a Kondo lattice with atomic resolution using a scanning tunneling microscope.

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Article Synopsis
  • Magnet/superconductor hybrids (MSHs) have potential to exhibit unique topological superconducting phases, including gapped superconductivity with zero-energy end states.
  • Recent studies suggested that the material 4Hb-TaS could be a gapless topological nodal-point superconductor (TNPSC), but no practical examples of TNPSCs in MSHs have been found until now.
  • This research demonstrates that stacking antiferromagnetic (AFM) monolayers on an s-wave superconductor creates a gapless superconducting state, confirmed by observations of edge modes at AFM island boundaries, paving the way for new 2D topological quantum phase designs.
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The possible realization of Majorana fermions as quasiparticle excitations in condensed-matter physics has created much excitement. Most studies have focused on Majorana bound states; however, propagating Majorana states with linear dispersion have also been predicted. Here, we report scanning tunneling spectroscopic measurements of crystalline domain walls (DWs) in FeSeTe We located DWs across which the lattice structure shifts by half a unit cell.

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