相关论文: Surface reconstruction and energy gap of supercond…
We made point-contact measurements with Au tips on La_{2-x}Sr_{x}CuO_{4} samples with 0.08 < x < 0.20 to investigate the relationship between superconducting gap and pseudogap. We obtained junctions whose conductance curves presented…
Recent photoemission experiments on the Si(553)-Au reconstruction show a one-dimensional band with a peculiar ~1/4 filling. This band could provide an opportunity for observing large spin-charge separation if electron-electron interactions…
We present a comprehensive investigation of reconstructions on $\beta$-Ga$_2$O$_3$(001) combining first-principles calculations with experimental observations. Using ab initio atomistic thermodynamics and replica-exchange grand-canonical…
We report directional point contact Andreev reflection (PCAR) measurements on high-quality single crystals of the non-centrosymmetric superconductor, BiPd. The PCAR spectra measured on different crystallographic faces of the single crystal…
The reconstruction on Ge(001) surface is locally and reversibly changed between c(4x2) and p(2x2) by controlling the bias voltage of a scanning tunneling microscope (STM) at 80K. It is c(4x2) with the sample bias voltage V_b =< -0.7V. This…
The crossed Andreev reflection in a hybrid nanostructure consisting of a d-wave superconductor and two quantum wires is theoretically studied. When the (110) oriented surface of the superconductor is in contact with the wires parallel and…
CrBr$_{3}$ is a layered van der Waals material with magnetic ordering down to the 2D limit. For decades, based on optical measurements, it is believed that the energy gap of CrBr$_{3}$ is in the range of 1.68-2.1 eV. However, controversial…
We report on the fabrication of highly transparent superconductor/normal metal/two-dimensional electron gas junctions formed by a superconducting NbN electrode, a thin (10nm) Au interlayer, and a two-dimensional electron gas in a InGaAs/InP…
We report on the optical generation and detection of ultrashort acoustic pulses that propagate in three-dimensional semiconductor crystals. Photoexcitaiton of lattice-matched GaP layers grown on Si(001) gives rise to a sharp spike in…
We investigate transport through hybrid structures consisting of two normal metal leads connected via tunnel barriers to one common superconducting electrode. We find clear evidence for the occurrence of non-local Andreev reflection and…
We present a first-principles study of the unreconstructed (001) surfaces of the half-metallic ferromagnet NiMnSb. Both terminations (MnSb and Ni) are considered. We find that half-metallicity is lost at the surfaces. After a discussion of…
We study superconducting quantum interference in InSb flake Josephson junctions. An even-odd effect in the amplitude and periodicity of the superconducting quantum interference pattern is found. Interestingly, the occurrence of this pattern…
We discuss basics of scanning tunneling microscopy and spectroscopy (STM/S) of the superconducting state with normal and superconducting tips. We present a new method to measure the local variations in the Andreev reflection amplitude…
A clean Si(001) surface thermally purified in an ultrahigh vacuum molecular-beam epitaxy chamber has been investigated by means of scanning tunneling microscopy. The morphological peculiarities of the Si(001) surface have been explored in…
We present a formulation of the quasiclassical theory of junctions between itinerant antiferromagnets (AF) and s-wave (sSC) and d-wave superconductors (dSC). For the simplest two-sublattice antiferromagnet on a bipartite lattice, we derive…
Topological superconductors host new states of quantum matter which show a pairing gap in the bulk and gapless surface states providing a platform to realize Majorana fermions. Recently, alkaline-earth metal Sr intercalated Bi2Se3 has been…
Reflection of charge excitations at the step in the interaction strength in a Luttinger liquid can be of the Andreev type, even if the interactions are purely repulsive. The region with stronger repulsion plays the role of a normal metal in…
The atomic and electronic structures of a graphene layer on top of the $(2\times2)$ reconstruction of the SiC (000$\bar{1}$) surface are studied from ab initio calculations. At variance with the (0001) face, no C bufferlayer is found here.…
Tunneling and optical transmission studies have been performed on superconducting samples of Rb3C60. At temperatures much below the superconducting transition temperature Tc the energy gap is 2 Delta=5.2 +- 0.2meV, corresponding to 2…
Phase- and voltage bias-sensitive quasiparticle transport at a double $NIS_1IS_2$ interface is considered. The barriers $I$ range from tunnel to transparent, and the intermediate region $S_1$ has a width comparable to the superconducting…