Penetration Depth Study of Superconducting Gap Structure of<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mn>2</mml:mn><mml:mi>H</mml:mi><mml:mtext mathvariant="normal">−</mml:mtext><mml:msub><mml:mi>NbSe</mml:mi><mml:mn>2</mml:mn></mml:msub></mml:math>

Fletcher, J. D.; Carrington, A.; Diener, P.; Rodière, Pierre; Brison, Jean-Pascal; Prozorov, Ruslan; Olheiser, T.; Giannetta, R. W.

doi:10.1103/physrevlett.98.057003

Cited by 126 publications

(101 citation statements)

References 18 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This result has explained the apparent discrepancy between angular resolved photoemission (ARPES) and London penetration measurements about the presence or not of a superconducting gap in the small 3D pocket derived form Se bands. Whereas ARPES does not observe gap opening in this band at temperatures very close to T c [129], London penetration depth measurements at much lower temperatures [130] did show evidence for the presence of a sizeable gap opening in the Se band. Furthermore, the spatial variation of the quasiparticle peaks obtained using superconducting tips give a length scale, termed Doppler shift length scale, related to the screening currents around vortex cores, and thus more to λ than to ξ [126].…”

Section: Superconducting Tipsmentioning

confidence: 72%

Imaging superconducting vortex cores and lattices with a scanning tunneling microscope

Suderow¹,

Guillamón²,

Rodrigo³

et al. 2014

Supercond. Sci. Technol.

101

View full text Add to dashboard Cite

Abstract. The observation of vortices in superconductors was a major breakthrough in developing the conceptual background for superconducting applications. Each vortex carries a flux quantum, and the magnetic field radially decreases from the center. Techniques used to make magnetic field maps, such as magnetic decoration, give vortex lattice images in a variety of systems. However, strong type II superconductors allow penetration of the magnetic field over large distances, of order of the magnetic penetration depth λ. Superconductivity survives up to magnetic fields where, for imaging purposes, there is no magnetic contrast at all. Static and dynamic properties of vortices are largely unknown at such high magnetic fields. Reciprocal space studies using neutron scattering have been employed to obtain insight into the collective behavior. But the microscopic details of vortex arrangements and their motion remain difficult to obtain. Direct real space visualization can be made using scanning tunneling microscopy and spectroscopy (STM/S). Instead of using magnetic contrast, the electronic density of states describes spatial variations of the quasiparticle and pair wavefunction properties. These are of order of the superconducting coherence length ξ, which is much smaller than λ. In principle, individual vortices can be imaged using STM up to the upper critical field where vortex cores, of size ξ, overlap. In this review, we describe recent advances in vortex imaging made with scanning tunneling microscopy and spectroscopy. We introduce the technique and discuss vortex images which reveal the influence of the Fermi surface distribution of the superconducting gap on the internal structure of vortices, the collective behavior of the lattice in different materials and conditions, and the observation of vortex lattice melting. We consider challenging lines of work, which include imaging vortices in nanostructures, multiband and heavy fermion superconductors, single layers and van-der-Waals crystals, studying current driven dynamics and the liquid vortex phases.

show abstract

Section: Superconducting Tipsmentioning

confidence: 72%

Imaging superconducting vortex cores and lattices with a scanning tunneling microscope

Suderow¹,

Guillamón²,

Rodrigo³

et al. 2014

Supercond. Sci. Technol.

101

View full text Add to dashboard Cite

show abstract

“…For instance, a CDW can be accompanied by a metal-to-insulator transition or be connected to low-temperature superconductivity [37,38]. Other materials with a CDW are the transition-metal dichalcogenides such as 2H − NbSe 2 and related compounds [38][39][40][41]. These have a layered hexagonal structure.…”

Section: Discussionmentioning

confidence: 99%

Charge density wave in layeredLa1−xCexSb2

et al. 2015

View full text Add to dashboard Cite

The layered rare-earth diantimonides RSb 2 are anisotropic metals with generally low electronic densities whose properties can be modified by substituting the rare earth. LaSb 2 is a nonmagnetic metal with a low residual resistivity presenting a low-temperature magnetoresistance that does not saturate with the magnetic field. It has been proposed that the latter can be associated to a charge density wave (CDW), but no CDW has yet been found. Here we find a kink in the resistivity above room temperature in LaSb 2 (at 355 K) and show that the kink becomes much more pronounced with substitution of La by Ce along the La 1−x Ce x Sb 2 series. We find signatures of a CDW in x-ray scattering, specific heat, and scanning tunneling microscopy (STM) experiments in particular for x ≈ 0.5. We observe a distortion of rare-earth-Sb bonds lying in-plane of the tetragonal crystal using x-ray scattering, an anomaly in the specific heat at the same temperature as the kink in resistivity and charge modulations in STM. We conclude that LaSb 2 has a CDW which is stabilized in the La 1−x Ce x Sb 2 series due to substitutional disorder.

show abstract

“…Such a "two-gap scenario" is qualitatively consistent with what k-integrated experimental probes tend to measure. [6][7][8][9]12,13 Intriguingly, the Fermi-surface-sheet selectivity of the gap comes along with a significant variation of the gap along the various Nb pockets. 12,16,17 The qualitative behavior is illustrated in Figs.…”

Section: Gap Structurementioning

confidence: 99%