Conductance

About: Conductance is a research topic. Over the lifetime, 8088 publications have been published within this topic receiving 235961 citations.

Theory of Tunneling Conductance for Normal Metal/Insulator/ Triplet Superconductor Junction

Abstract: Tunneling conductance spectra of normal metal/insulator/triplet superconductor junctions are investigated theoretically As triplet paring states we select several types of symmetries that are promising candidates for the superconducting states in UPt 3 and in Sr 2 RuO 4 The calculated conductance spectra are sensitive to the orientation of the junction which reflects the anisotropy of the pairing states They show either zero-bias conductance peaks or gap-like structures depending on the orientation of the junctions The existence of a residual density of states, peculiar to nonunitary states, is shown to have a significant influence on the properties of the conductance spectra Present results serve as a guide for the experimental determination of the symmetry of the pair potentials in UPt 3 and Sr 2 RuO 4

Quantum transport through a DNA wire in a dissipative environment.

Abstract: Electronic transport through DNA wires in the presence of a strong dissipative environment is investigated. We show that new bath-induced electronic states are formed within the band gap. These states show up in the linear conductance spectrum as a temperature dependent background and lead to a crossover from tunneling to thermal activated behavior with increasing temperature. Depending on the strength of the electron-bath coupling, the conductance at the Fermi level can show a weak exponential or even an algebraic length dependence. Our results suggest a new environmentally induced transport mechanism. This might be relevant for the understanding of molecular conduction experiments in liquid solution, such as those recently performed on poly(GC) oligomers in a water buffer (B. Xu et al., Nano Lett. 2004, 4, 1105).

Conductivity and Dielectric Relaxation in Concentrated Aqueous Lithium Chloride Solutions

Abstract: This paper describes a study of the recently recognized phenomenon of conductivity relaxation in liquid electrolytes as it is observed in the system LiCl+water. Advantage has been taken of the supercooling ability of 6–20m solutions in this system to reduce solution temperatures to the vicinity of −100°C and thereby to increase the relaxation time characteristic of the conductance process sufficiently to permit its study with conventional ac conductance bridges operating in the frequency range 0.2–2 000 kHz. Extensive data are presented for four solutions in the concentration range 8.3–11.9m. When the frequency‐dependent conductance and capacitance data are analyzed in the dielectric modulus notation developed by Macedo, Bose, and Litovitz, mean relaxation times for conductance are obtained which have a non‐Arrhenius temperature dependence identical to that of the dc conductivity. Earlier studies of dielectric relaxation in these solutions, carried out at room temperature and gigahertz frequencies, are re...

Nonlocal Conductance Spectroscopy of Andreev Bound States: Symmetry Relations and BCS Charges.

Abstract: Two-terminal conductance spectroscopy of superconducting devices is a common tool for probing Andreev and Majorana bound states. Here, we study theoretically a three-terminal setup, with two normal leads coupled to a grounded superconducting terminal. Using a single-electron scattering matrix, we derive the subgap conductance matrix for the normal leads and discuss its symmetries. In particular, we show that the local and the nonlocal elements of the conductance matrix have pairwise identical antisymmetric components. Moreover, we find that the nonlocal elements are directly related to the local BCS charges of the bound states close to the normal probes and we show how the BCS charge of overlapping Majorana bound states can be extracted from experiments.

Quantum interference and heteroaromaticity of para-and meta-linked bridged biphenyl units in single molecular conductance measurements

Abstract: Is there a correlation between the (hetero)aromaticity of the core of a molecule and its conductance in a single molecular junction? To address this question, which is of fundamental interest in molecular electronics, oligo(arylene-ethynylene) (OAE) molecular wires have been synthesized with core units comprising dibenzothiophene, carbazole, dibenzofuran and fluorene. The biphenyl core has been studied for comparison. Two isomeric series have been obtained with 4-ethynylpyridine units linked to the core either at para-para positions (para series 1–5) or meta-meta positions (meta series 6–10). A combined experimental and computational study, using mechanically controlled break junction measurements and density functional theory calculations, demonstrates consistently higher conductance in the para series compared to the meta series: this is in agreement with increased conjugation of the π–system in the para series. Within the para series conductance increases in the order of decreasing heteroaromaticity (dibenzothiophene < carbazole < dibenzofuran). However, the sequence is very different in the meta series, where dibenzothiophene ≈ dibenzofuran < carbazole. Excellent agreement between theoretical and experimental conductance values is obtained. Our study establishes that both quantum interference and heteroaromaticity in the molecular core units play important and inter-related roles in determining the conductance of single molecular junctions.