Fractional Conductance Quantization in Metallic Nanoconstrictions under Electrochemical Potential Control

Abstract

We study the electrical conductance of gold nanoconstrictions by controlling the electrochemical potential. At positive potentials, the conductance is quantized near integer multiples of G0(2e(2)/h) as shown by well-defined peaks in the conductance histogram. Below a certain potential, however, additional peaks near 0.5G(0) and 1. 5G(0) appear in the histogram. The fractional conductance steps are as stable and well defined as the integer steps. The experimental data are discussed in terms of electrochemical-potential-induced defect scattering and Fermi energy shift, but a complete theory of the phenomenon is yet to be developed.

Magnetoresistance of the ferromagnetic nanocontacts fabricated by electrodeposition

“…The issue with a micro-gap prepared in this way is that the copper is 20 μm thick. Figure 2 shows the resistance feedback controlled electroplating process [20]. In this figure, the working electrodes (W 1 and W 2 ) are the two copper film electrodes, CE is the Pt counter electrode, and REF is the saturated calomel electrode.…”

Fabrication of stable metal nanowire showing conductance quantization in solution

“…These facts make possible to fabricate very stable metal nanowires, which has not been prepared in UHV. Fabrication of stable Au, Ag, Cu, Pb, Fe, Co, Ni, and Pd nanowires and interesting phenomena characteristic of the electrochemical system have been reported in solution at room temperature [3][4][5][6][7]. Although a Cu nanowire in a solution was more stable than that in UHV at room temperature, the stretched length of the nanowire was still rather short, typically less than 0.1 nm.…”

“…Recently, the electrochemical method has been recognized to be a powerful approach to fabricate stable metal nanowires [3][4][5][6][7]. Electrochemical potential determines the potential energy of the electrons of the nanowires, resulting in the control of the bonding strength between the metal atoms, and the interaction of the metals with molecules of surrounding medium.…”

Electric conductance of metal nanowires at mechanically controllable break junctions under electrochemical potential control

“…Recently, preparation of metal nanowires under electrochemical potential control has attracted wide attention [9][10][11][12][13]. Electrochemical potential determines the potential energy of electrons in metal nanowires, resulting in control of the bonding strength between the metal atoms in the wires and the interaction between the metals and molecules in the surrounding medium.…”

“…These characteristics lead to successful fabrication of very stable metal nanowires, which cannot be prepared in UHV. Relatively stable Au [9], Ag, Cu, Pb [10], Fe, Co, Ni [11], and Pd [12] metal nanowires were fabricated in solution at room temperature with the aid of electrochemical potential control. Furthermore, the stability and structure of Au mono atomic wires was controlled by the electrochemical potential [13].…”