Proximity superconductivity in atom-by-atom crafted quantum dots
arXiv:2212.00657 · doi:10.1038/s41586-023-06312-0
Abstract
Gapless materials in electronic contact with superconductors acquire proximity-induced superconductivity in a region near the interface. Numerous proposals build on this addition of electron pairing to originally non-superconducting systems like ferromagnets and predict intriguing quantum phases of matter, including topological-, odd-frequency-, or nodal-point superconductivity. However, atomic-scale experimental investigations of the microscopic mechanisms leading to proximity-induced Cooper pairing in surface or interface states are missing. Here, we investigate the most miniature example of the proximity effect on only a single quantum level of a surface state confined in a quantum corral on a superconducting substrate, built atom-by-atom by a scanning tunneling microscope. Whenever an eigenmode of the corral is pitched close to the Fermi energy by adjusting the corral's size, a pair of particle-hole symmetric states enters the superconductor's gap. We identify the in-gap states as scattering resonances theoretically predicted 50 years ago by Machida and Shibata, which had so far eluded detection. We further show that the observed anticrossings of the in-gap states indicate proximity-induced pairing in the quantum corral's eigenmodes. Our results have direct consequences on the interpretation of in-gap states in unconventional or topological superconductors, corroborate concepts to induce superconductivity into a single quantum level and further pave the way towards superconducting artificial lattices.
References in corpus (35)
- Superconducting proximity effect and Majorana fermions at the surface of a topological insulator
- Odd Triplet Superconductivity and Related Phenomena in Superconductor-Ferromagnet Structures
- Imaging the Effects of Individual Zinc Impurity Atoms on Superconductivity in Bi2Sr2CaCu2O8+delta
- Spin-polarized supercurrents for spintronics: a review of current progress
- Experimental realization and characterization of an electronic Lieb lattice
- Topological superconductivity in a van der Waals heterostructure
- Topological states in engineered atomic lattices
- Design and characterization of electronic fractals
- Robust zero-energy modes in an electronic higher-order topological insulator: the dimerized Kagome lattice
- Atom Transfer and Single-Adatom Contacts
- Single magnetic adsorbates on s-wave superconductors
- Atomic-Scale Interface Engineering of Majorana Edge Modes in a 2D Magnet-Superconductor Hybrid System
- Observation of a Majorana zero mode in a topologically protected edge channel
- Impurity-Induced Bound Excitations on the Surface of Bi2Sr2CaCu2O8
- Role of bulk and surface phonons in the decay of metal surface states
- Higher Order Topology and Nodal Topological Superconductivity in Fe(Se,Te) Heterostructures
- Designer quantum states of matter created atom-by-atom
- Signature of a pair of Majorana zero modes in superconducting gold surface states
- Proximity-induced superconducting gap in the quantum spin Hall edge state of monolayer WTe
- Evidence of topological Shiba bands in artificial spin chains on superconductors
- Topological Superconductivity and Majorana Fermions in Metallic Surface-States
- Suppressed Charge Dispersion via Resonant Tunneling in a Single-Channel Transmon
- Observation of vanishing charge dispersion of a nearly-open superconducting island
- p Orbital flat band and Dirac cone in the electronic honeycomb lattice
- On the preparation and electronic properties of clean superconducting Nb(110) surfaces
- Edge-dependent topology in Kekulé lattices
- Charge of a quasiparticle in a superconductor
- Atomic scale shot-noise using broadband scanning tunnelling microscopy
- Bogoliubov angle and visualization of particle-hole mixture in superconductors
- Interplay Between Yu-Shiba-Rusinov States and Multiple Andreev Reflections
- Quantifying many-body effects by high-resolution Fourier transform scanning tunneling spectroscopy
- Superconductivity of lanthanum revisited: enhanced critical temperature in the clean limit
- Two-band superconductivity of bulk and surface states in Ag thin films on Nb
- Lifetime reduction of surface states at Cu, Ag and Au(111) caused by impurity scattering
- Selective Trapping of Hexagonally Warped Topological Surface States in a Triangular Quantum Corral
Cited by in corpus (9)
- Majorana quasiparticles in atomic spin chains on superconductors
- Roadmap on Nanoscale Superconductivity for Quantum Technologies
- Signatures of Kondo-Majorana interplay in ac response
- Floquet-engineered diode performance in a Majorana-quantum dot Josephson junction
- Spatially Dependent in-Gap States Induced by Andreev Tunneling through a Single Electronic State
- Control of Andreev Reflection via a Single-Molecule Orbital
- Quantum-size effect induced Andreev bound states in ultrathin metallic islands proximitized by a superconductor
- Time-reversal symmetric topological superconductivity in Machida-Shibata lattices
- Scanning Tunneling Microscopy in high vectorial magnetic fields