arXiv subjects

Xin-Hai Tu

Publications and source records attributed to Xin-Hai Tu.

3 recordsLinked to original sources

arXiv2021

Topological Superconductivity in Rashba Spin-Orbital Coupling Suppressed Monolayer \{beta}-Bi2Pd

The weak interlayer Van Der Waals material \{beta}-Bi2Pd has recently been established as a strong topological superconductor candidate with unconventional spin-triplet pairing and Majorana zero modes at vortices. In this letter, we study the topological characters and the superconducting pairing, which are still obscure in monolayer \{beta}-Bi2Pd, in light of our effective theoretical model. We find that the non-Rashba spin-orbital coupling plays a critical role in realizing and tuning various novel topological natures. In particular, the spin-triplet p-wave superconducting pairing with Majorana zero mode is revealed in monolayer \{beta}-Bi2Pd. Our studies deepen the understanding of topology and superconductivity in monolayer \{beta}-Bi2Pd and indicate it is a promising platform for achieving low-dimentional topological superconductivity.

cond-mat.mes-hall↗

arXiv2020

Prediction of superconductivity and topological aspects in single-layer $β$-Bi$_{2}$Pd

Topological superconductors, characterized by topologically nontrivial states residing in a superconducting gap, are a recently discovered class of materials having Majorana Fermions. The interplay of superconductivity and topological states give rise to opportunities for achieving such topological superconductors in condensed matter systems. Up to now, several single-material topological superconductors in this form have been theoretically predicted and experimentally confirmed. Here, using the first-principles calculations, we study the superconducting single-layer $β$-Bi$_{2}$Pd. The electronic density of states near Fermi level of this monolayer are dominated by the Bi-p and Pd-d orbitals, forming a two-band Fermi surface with multi-class sheets. The presence of soft phonon bands, in cooperation with the electron susceptibility, account for electron-phonon superconductivity of single-layer $β$-Bi$_{2}$Pd. With the centrosymmetric structure, single-layer $β$-Bi$_{2}$Pd possesses a continuous gap over the whole Brillouin zone and topological Dirac-like states at its one-dimensional boundary. The present findings would lead to the expectation of one-dimensional topological superconductivity and Majorana bound states in monolayer candidate of $β$-Bi$_{2}$Pd with intrinsic full-gap superconductivity.

cond-mat.mtrl-sci↗

arXiv2020

Inelastic electron tunneling in 2H-Ta$_x$Nb$_{1-x}$Se$_2$ evidenced by scanning tunneling spectroscopy

We report a detailed study of tunneling spectra measured on 2H-Ta$_x$Nb$_{1-x}$Se$_2$ ($x=0\sim 0.1$) single crystals using a low-temperature scanning tunneling microscope. The prominent gap-like feature unintelligible for a long time was found to be accompanied by some "in-gap" fine structures. By investigating the second-derivative spectra and their temperature and magnetic field dependencies, we were able to prove that inelastic electron tunneling is the origin of these features and obtain the Eliashberg function of 2H-Ta$_x$Nb$_{1-x}$Se$_2$ at atomic scale, providing a potential way to study the local Eliashberg function and phonon spectra of the related transition-metal dichalcogenides.

cond-mat.mtrl-sci↗