Scanning tunneling microscopic observation of enhanced superconductivity in epitaxial Sn islands grown on SrTiO3 substrate

Strongly Compressed Few-Layered SnSe2 Films Grown on a SrTiO3 Substrate: The Coexistence of Charge Ordering and Enhanced Interfacial Superconductivity

“…The possibly underlying enhanced electron–phonon coupling from SrTiO 3 may also play a role in this superconducting enhancement, but no relevant evidence have been observed so far. Besides, the extremely large critical magnetic field is naturally reminiscent of our previous work of Sn islands grown on a SrTiO 3 substrate, in which superconducting gap can even persist up to 8 T, because of the size effect and decreased electron mean-free path . The existence of apparent phase separation in bilayer films can induce strong electron scattering, resulting in the formation of a V-shaped superconducting gap instead of a U-shape, while reduce the electron mean-free path.…”

“…Besides, the extremely large critical magnetic field is naturally reminiscent of our previous work of Sn islands grown on a SrTiO 3 substrate, in which superconducting gap can even persist up to 8 T, because of the size effect and decreased electron meanfree path. 50 The existence of apparent phase separation in bilayer films can induce strong electron scattering, resulting in the formation of a V-shaped superconducting gap instead of a U-shape, while reduce the electron mean-free path. A small electron mean-free path can decrease the superconducting coherence length ξ and increase the effective penetration length λ, leading to a much higher magnetic field, which is needed to destroy superconductivity.…”

Layer-Stacking, Defects, and Robust Superconductivity on the Mo-Terminated Surface of Ultrathin Mo2C Flakes Grown by CVD

“…Notably, the deduced T c = 8.0 K of the α-Mo 2 C flake with a thickness of 13.1 nm is almost two times higher than the previously reported highest T c value (about 4.0 K), investigated by the transport measurements in the film thicknesses ranging from 3.4 to 40 nm. ,, As revealed by our STM images, considerable strain appeared on these α-Mo 2 C flakes grown directly on the liquid Cu. A strained lattice in 2D materials could enhance the superconductivity, such as the epitaxial films grown on specific substrates. − The large BCS ratio 2Δ(0) k B T c also indicates an enhanced coupling mechanism, which suggests that the strain may play an important role in enhancing the superconductivity. On the other hand, the observed layer stacking modes and the lattice defects will both lead to the increase of disorder and give rise to a shorter coherence length obtained here.…”

Quantum well electronic states in spatially decoupled 2D Pb nanoislands on Nb-doped SrTiO3(0 0 1)

“…Since the discovery of high-temperature superconductivity in one-unit-cell FeSe film grown on Nbdoped SrTiO 3 (001) (Nb-STO) 1 , i.e., superconducting transition temperature T C dramatically increases up to 109 K, the enhancement of T C by interface effects has been reported on various Fe-based superconducting ultrathin films prepared on pervoskite-type titanium oxide substrates [2][3][4][5] . Besides the unconventional Fe-based superconductors, the elementary β-Sn islands self-assembled on the Nb-STO(001) substrate also exhibit an improved T C up to 8.2 K as compared to the bulk T C about 3.7 K, which has been attributed to the interfacial charge transfer as well as enhanced electron-phonon coupling at the nanometer-sized β-Sn islands 6 .…”