By introducing a superconducting gap in Weyl or Dirac semimetals, the superconducting state inherits the nontrivial topology of their electronic structure. As a result, Weyl superconductors are expected to host exotic phenomena, such as nonzero-momentum pairing due to their chiral node structure, or zero-energy Majorana modes at the surface. These are of fundamental interest to improve our unde...

– We performed the local spectroscopy of a Normal-metal–Superconductor (N-S) junction with the help of a very low temperature (60 mK) Scanning Tunneling Microscope (STM). The spatial dependence of the local density of states was probed locally in the vicinity of the N-S interface. We observed spectra with a fully-developed gap in the regions where a thin normal metal layer caps the superconduct...

Relationships between the superconducting gap, pseudogap and transition temperature in high-T c superconductors Abstract The crossover from superconducting gap to pseudogap is considered. We show that the superconductivity is destroyed at the temperature T c , with the superconducting gap being smoothly transformed into the pseudogap. Relations, which are of general interest, between the maximu...

The microscopic mechanism governing the zero-resistance flow of current in some iron-based, high-temperature superconducting materials is not well understood up to now. A central issue concerning the investigation of these materials is their superconducting gap symmetry and structure. Here we present a combined study of low-temperature specific heat and scanning tunnelling microscopy measuremen...

Andreev billiards are finite, arbitrarily shaped, normal-state regions, surrounded by superconductor. At energies below the superconducting energy gap, single-quasiparticle excitations are confined to the normal region and its vicinity, the mechanism for confinement being Andreev reflection. Short-wave quantal properties of these excitations, such as the connection between the density of states...

We have fabricated single-Cooper-pair transistors in which the spatial profile of the superconducting gap energy was controlled by oxygen doping. The profile dramatically affects the switching current vs gate voltage curve of the transistor, changing its period from 1e to 2e. A model based on nonequilibrium quasiparticles in the leads explains our results, including the observation that even de...

Although the low-frequency electronic Raman response in the superconducting state of the cuprates can be largely understood in terms of a d-wave energy gap, a long-standing problem has been an explanation for the spectra observed in the A1g polarization orientations. We present calculations which suggest that the peak position of the observed A1g spectra is due to a collective spin fluctuation ...

abstract in this paper, a fuzzy pid with new structure is proposed to solve the load frequency control in interconnected power systems. in this study, a new structure and effective of the fuzzy pid-type load frequency control (lfc) is proposed to solve the load frequency control in interconnected power systems. the main objective is to eliminate the deviations in the frequency of different area...

The state variables of an electrical circuit, like voltages and currents can be made to behave quantum mechanically by minimizing the coupling to external degrees of freedom through a proper design. Circuits based on superconducting tunnel junctions have displayed signatures of macroscopic quantum behavior [1–7], but the level of coherence of the quantum states remained until now much smaller t...

This thesis reports measurements concerning quantum size effects of single crystalline metallic islands by using low-temperature scanning tunneling microscopy (STM) and spectroscopy (STS). Different sample systems are presented in the following chapters. In chapter 2, several aspects of quantum well states (QWS) of Pb ultrathin islands grown on Si(111) substrate are reported. The differential c...