We show that quasiparticle interference (QPI) due to omnipresent weak impurities and probed by Fourier transform scanning tunneling microscopy and spectroscopy acts as a direct experimental probe of bulk odd-frequency superconducting pairing. Taking the example of a conventional s-wave superconductor under applied magnetic field, we show that the nature of the QPI peaks can only be characterized by including the odd-frequency pairing correlations generated in this system. In particular, we identify that the defining feature of odd-frequency pairing gives rise to a bias asymmetry in the QPI, present generically in materials with odd-frequency pairing irrespective of its origin.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1103/PhysRevLett.129.247001 | DOI Listing |
Nature
September 2023
Department of Physics, Universität Hamburg, Hamburg, Germany.
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 and predict intriguing phases of matter, including topological, odd-frequency, nodal-point or Fulde-Ferrell-Larkin-Ovchinnikov superconductivity. Here we investigate the most miniature example of the proximity effect on only a single spin-degenerate quantum level of a surface state confined in a quantum corral on a superconducting substrate, built atom by atom by a scanning tunnelling microscope.
View Article and Find Full Text PDFNanoscale
May 2023
Department of Electrophysics & Center for Emergent Functional Matter Science, National Yang Ming Chiao Tung University, Hsinchu 30010, Taiwan.
We report the observation of enhanced interfacial two-component superconductivity possessing a dominant triplet component in nonmagnetic CoSi/TiSi superconductor/normal-metal planar heterojunctions. This is accomplished through the detection of odd-frequency spin-triplet even-parity Cooper pairs in the diffusive normal-metal component of T-shaped proximity junctions. We show that by modifying the diffusivity of the normal-metal part, the transition temperature enhancement can be tuned by a factor of up to 2.
View Article and Find Full Text PDFSci Adv
March 2023
Institute for Molecules and Materials, Radboud University, 6525 AJ Nijmegen, Netherlands.
BCS theory has been widely successful at describing elemental bulk superconductors. Yet, as the length scales of such superconductors approach the atomic limit, dimensionality as well as the environment of the superconductor can lead to drastically different and unpredictable superconducting behavior. Here, we report a threefold enhancement of the superconducting critical temperature and gap size in ultrathin epitaxial Al films on Si(111), when approaching the 2D limit, based on high-resolution scanning tunneling microscopy/spectroscopy (STM/STS) measurements.
View Article and Find Full Text PDFPhys Rev Lett
December 2022
Department of Physics and Astronomy, Uppsala University, Box 516, S-751 20 Uppsala, Sweden.
We show that quasiparticle interference (QPI) due to omnipresent weak impurities and probed by Fourier transform scanning tunneling microscopy and spectroscopy acts as a direct experimental probe of bulk odd-frequency superconducting pairing. Taking the example of a conventional s-wave superconductor under applied magnetic field, we show that the nature of the QPI peaks can only be characterized by including the odd-frequency pairing correlations generated in this system. In particular, we identify that the defining feature of odd-frequency pairing gives rise to a bias asymmetry in the QPI, present generically in materials with odd-frequency pairing irrespective of its origin.
View Article and Find Full Text PDFPhys Rev Lett
October 2022
Division of Condensed Matter Physics and Materials Science, Brookhaven National Laboratory, Upton, New York 11973-5000, USA.
The Kondo lattice model plays a key role in our understanding of quantum materials, but a lack of small parameters has posed a long-standing problem. We present a three-dimensional S=1/2 Kondo lattice model describing a spin liquid within an electron sea. Strong correlations in the spin liquid are treated exactly, enabling a controlled analytical approach.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!