Observation of Coexisting Weak Localization and Superconducting Fluctuations in Strained Sn_1–xIn_xTe Thin Films

Abstract

Topological superconductors have attracted tremendous excitement as they are predicted to host Majorana zero modes that can be utilized for topological quantum computing. Candidate topological superconductor Sn1–x In x Te thin films (0 < x < 0.3) grown by molecular beam epitaxy and strained in the (111) plane are shown to host quantum interference effects in the conductivity coexisting with superconducting fluctuations above the critical temperature T c. An analysis of the normal state magnetoresistance reveals these effects. A crossover from weak antilocalization to localization is consistently observed in superconducting samples, indicating that superconductivity originates dominantly from charge carriers occupying trivial states that may be strongly spin–orbit split. A large enhancement of the conductivity is observed above T c, indicating the presence of superconducting fluctuations. Our results motivate a re-examination of the debated pairing symmetry of this material when subjected to quantum confinement and lattice strain.

Probing electron-electron interaction along with superconducting fluctuations in disordered TiN thin films

“…Here, 𝜏 𝜙 introduces phase breaking processes due to mainly inelastic scattering (as spin-flip scattering can be ignored) [27,28] and 𝛽(𝑇 𝑇 𝑐 ⁄ ) relates to the strength function characterizing electron-electron interaction which has been introduced by Larkin [16]. Summing up all the aforementioned contributions related to the total quantum corrections to the conductivity (QCC), the experimental data from T* (deviation point from WL+ID fitting) to the lowest available temperature can be fitted by using the following equation,…”

“…Here, 𝜏 𝜙 is dephasing scattering time and the associated magnetic field (𝐵 𝜙 ) is known as the phasebreaking field, and D is the diffusion constant. The coefficient N in equation ( 12) represents the number of channels participating in the conduction process [28]. Further, we have calculated magnetoconductance from the measured longitudinal magnetoresistance with resistance in Ohm/Square by using the given expression,…”

Persistence of symmetry-protected Dirac points at the surface of the topological crystalline insulator SnTe upon impurity doping

“…Doped SnTe, specially by In impurities, is an ongoing subject of discussion regarding topological superconductivity. 23 Impurities in TCI thin films may open a gap or modify the surface states, allowing for the control of topological phase transitions in these materials and constituting an additional tool to modulate their properties. 24,25 Indeed, tuning the electronic properties by doping or by applied external fields opens a way for the application of these materials in nanoscale devices.…”

“…Doped SnTe, specially by In impurities, is an ongoing subject of discussion regarding topological superconductivity. 23…”

Confinement‐Enhanced Rashba Spin–Orbit Coupling at the LaAlO3/KTaO3 Interface via LaAlO3 Thickness Control

“…Apparently, the fitted curve substantially deviates from the experimental MC data at 8 K of the 20 nm sample, while the MC data at 12 and 15 K are excellently fitted, as shown in Figure 3a. Meanwhile, in Figure 3b–d, the MC data of the 2, 5, and 10 nm samples are all fitted well above 8 K. The deviation in the fitting curve of the 20 nm sample at 8 K might originate from the superconducting fluctuation [ 38 ] or other unknown reasons.…”