Spin-resolved spectra of Shiba multiplets from Mn impurities in<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:msub><mml:mrow><mml:mtext>MgB</mml:mtext></mml:mrow><mml:mn>2</mml:mn></mml:msub></mml:mrow></mml:math>

Moca, Cătălin Paşcu; Demler, Eugene; Jankó, Boldizsár; Zaránd, Gergely

doi:10.1103/physrevb.77.174516

Cited by 41 publications

(44 citation statements)

References 33 publications

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“…For a conventional superconductor like MgB 2 discussed here, a nonmagnetic impurity could not affect superconductivity much as predicted by early Anderson's theorem 37 , which means no bound state would be introduced by a nonmagnetic impurity. On the other hand, magnetic impurity can give rise to pairs of bound states both above and below E F , also called Shiba states 32,38,39 . The energy positions of the Shiba states vary with scattering details.…”

Section: −11mentioning

confidence: 99%

Momentum dependence of the superconducting gap and in-gap states inMgB2multiband superconductor

et al. 2015

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We use tunable laser based Angle Resolved Photoemission Spectroscopy to study the electronic structure of the multi-band superconductor, MgB2. These results form the base line for detailed studies of superconductivity in multi-band systems. We find that the magnitude of the superconducting gap on both σ bands follows a BCS-like variation with temperature with ∆0 ∼ 7 meV. The value of the gap is isotropic within experimental uncertainty and in agreement with pure a s-wave pairing symmetry. We also observe in-gap states confined to kF of the σ band that occur at some locations of the sample surface. The energy of this excitation, ∼ 3 meV, is inconsistent with scattering from the π band.

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Section: −11mentioning

confidence: 99%

Momentum dependence of the superconducting gap and in-gap states inMgB2multiband superconductor

et al. 2015

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“…The symmetry reduction by crystal fields, and hybridization with the host atomic lattice lift the degeneracy of the l =2 subshell. In this scenario, Shiba multiplets are predicted to appear, thus reflecting the occupation level of the atomic shell16. The resolution of their orbital character would render them as the ideal probe for identifying the magnetic ground state of a single impurity in a superconductor.…”

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confidence: 99%

Mapping the orbital structure of impurity bound states in a superconductor

et al. 2017

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A magnetic atom inside a superconductor locally distorts superconductivity. It scatters Cooper pairs as a potential with broken time-reversal symmetry, leading to localized bound states with subgap excitation energies, named Shiba states. Most conventional approaches regarding Shiba states treat magnetic impurities as point scatterers with isotropic exchange interaction. Here, we show that the number and the shape of Shiba states are correlated to the spin-polarized atomic orbitals of the impurity, hybridized with the superconductor. Using scanning tunnelling spectroscopy, we spatially map the five Shiba excitations found on subsurface chromium atoms in Pb(111), resolving their particle and hole components. While particle components resemble d orbitals of embedded Cr atoms, hole components differ strongly from them. Density functional theory simulations correlate the orbital shapes to the magnetic ground state of the atom, and identify scattering channels and interactions, all valuable tools for designing atomic-scale superconducting devices.

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“…Extending the two-impurity calculations to the case of a superconducting host represents an interesting and active challenge [8][9][10][11][12][13][14][15][16][17]. On the one hand, the interplay of superconductivity and magnetic moments can lead to the emergence of exotic phases and excitations.…”

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confidence: 99%

Phase diagram and excitations of a Shiba molecule

et al. 2014

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We analyze the phase diagram associated with a pair of magnetic impurities trapped in a superconducting host. The natural interplay between Kondo screening, superconductivity and exchange interactions leads to a rich array of competing phases, whose transitions are characterized by discontinuous changes of the total spin. Our analysis is based on a combination of numerical renormalization group techniques as well as semi-classical analytics. In addition to the expected screened and unscreened phases, we observe a new molecular doublet phase where the impurity spins are only partially screened by a single extended quasiparticle. Direct signatures of the various Shiba molecule states can be observed via RF spectroscopy.Comment: 13 pages, 7 figure

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Spin-resolved spectra of Shiba multiplets from Mn impurities inMgB2

Cited by 41 publications

References 33 publications

Momentum dependence of the superconducting gap and in-gap states inMgB2multiband superconductor

Momentum dependence of the superconducting gap and in-gap states inMgB2multiband superconductor

Mapping the orbital structure of impurity bound states in a superconductor

Phase diagram and excitations of a Shiba molecule

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