Quantum Conductance in Silicon Oxide Resistive Memory Devices

Abstract

Resistive switching offers a promising route to universal electronic memory, potentially replacing current technologies that are approaching their fundamental limits. In many cases switching originates from the reversible formation and dissolution of nanometre-scale conductive filaments, which constrain the motion of electrons, leading to the quantisation of device conductance into multiples of the fundamental unit of conductance, G0. Such quantum effects appear when the constriction diameter approaches the Fermi wavelength of the electron in the medium – typically several nanometres. Here we find that the conductance of silicon-rich silica (SiOx) resistive switches is quantised in half-integer multiples of G0. In contrast to other resistive switching systems this quantisation is intrinsic to SiOx, and is not due to drift of metallic ions. Half-integer quantisation is explained in terms of the filament structure and formation mechanism, which allows us to distinguish between systems that exhibit integer and half-integer quantisation.

Luminescent Devices Based on Silicon-Rich Dielectric Materials

“…This RS behavior is independent on the thermal annealing temperature [46]. Recent studies regarding the same electrical RS behavior in SRO ilms was observed and related with a conductive ilament formed by Si-nps [81][82][83][84], which undergoes structural changes through a crystallization and amorphization process of the Si-nps, as discussed in [82]. Such observations are in agreement with the presented asseverations about the behavior of the SRO with Ro = 30 (M30)-based LECs.…”

Structural changes and conductance thresholds in metal-free intrinsic SiOx resistive random access memory

“…Starting from the low resistance state, the device is swept to successively higher voltages, from 1.6 V to 2.5 V. A progressive fall in conductance is seen for the first 8 sweeps (1-8). We note that the conduction of these states is nonlinear, which we assign, as in our previous work, 25,26 to the existence of parallel conduction paths (a linear component coming from the conductive filament, and a non-linear component from surrounding partially formed semiconducting tissue) or a residual potential barrier between the oxide and the contact. Such a gradual reduction in conductance is consistent with a progressive thinning of an initially robust conductive filament by thermally driven re-oxidation of a weak switching point.…”

Bidirectional threshold switching characteristics in Ag/ZrO2/Pt electrochemical metallization cells

“…It is known that the electron transport is quantized in multiples of fundamental quantum of conductance G=2e 2 /h (e is the charge of the electron and h is Planck's constant) as the constriction diameter of filament being comparable to the Fermi wavelength of the electrons. [21][22][23] As illustrated in Fig. 2, the conductance G was calculated as G = I/V and recorded in units of G 0 .…”