Emergence of Exotic Spin Texture in Supramolecular Metal Complexes on a 2D Superconductor

Abstract

Designer heterostructures, where the desired physics emerges from the controlled interactions between different components, represent one of the most powerful strategies to realize unconventional electronic states. This approach has been particularly fruitful in combining magnetism and superconductivity to create exotic superconducting states. In this work, we use a heterostructure platform combining supramolecular metal complexes (SMCs) with a quasi-2D van der Waals (vdW) superconductor NbSe${}_2$. Our scanning tunneling microscopy (STM) measurements demonstrate the emergence of Yu-Shiba-Rusinov (YSR) bands arising from the interaction between the SMC magnetism and the NbSe${}_2$ superconductivity. Using X-ray absorption spectroscopy (XAS) and X-ray magnetic circular dichroism (XMCD) measurements, we show the presence of antiferromagnetic coupling between the SMC units. These result in the emergence of an unconventional $3\times 3$ reconstruction in the magnetic ground state that is directly reflected in real space modulation of the YSR bands. The combination of flexible molecular building blocks, frustrated magnetic textures, and superconductivity in heterostructures establishes a fertile starting point to fabricating tunable quantum materials, including unconventional superconductors and quantum spin liquids.

References in corpus (14)

• Quantum ESPRESSO: a modular and open-source software project for quantum simulations of materials
• Observation of Majorana Fermions in Ferromagnetic Atomic Chains on a Superconductor
• Fractional antiferromagnetic skyrmion lattice induced by anisotropic couplings
• Square skyrmion crystal in centrosymmetric itinerant magnets
• Controlled length-dependent interaction of Majorana modes in Yu-Shiba-Rusinov chains
• Hunting for Majoranas
• Engineering interfacial quantum states and electronic landscapes by molecular nanoarchitectures
• Quantum spins and hybridization in artificially-constructed chains of magnetic adatoms on a superconductor
• Quantized charge transport in chiral Majorana edge modes
• Two-dimensional Shiba lattices as possible platform for crystalline topological superconductivity
• A Two-Dimensional Metal-Organic Framework on Superconducting NbSe${}_2$
• Antiferromagnetism-driven two-dimensional topological nodal-point superconductivity
• Testing the topological nature of end states in antiferromagnetic atomic chains on superconductors
• Yu-Shiba-Rusinov bands in a self-assembled kagome lattice of magnetic molecules