Emergent Conductance Plateaus at Room Temperature in PET-Metal Fiber-Based Yarns

Abstract Quantized conductance is conventionally associated with nanoscale constrictions supporting a small number of channels with transmission probabilities approaching unity. Here, an industrially produced polyethylene terephthalate−stainless-steel (PET−SS) memristive yarn, without lithographically defined nanoscale constrictions, exhibits discrete conductance-state evolution during voltage sweeps at room temperature under ambient conditions. Across repeated voltage sweeps, the rolling standard deviation (SD) of resistance exhibits recurrent minima near several integer values of G/G0 (where G0 = 2e2/h), supporting an interpretation in terms of confined few-channel transport. The results suggest electrically driven formation of a confined high-transmission constriction within local SS−PET−SS microjunctions. A phenomenological Green’s-function model further illustrates that progressive activation of a limited number of effective transport pathways within a confined junction can produce discrete current evolution. When the device is first cooled to 77 K and subsequently electrically biased, memristive switching and discrete conductance changes remain observable, whereas the room-temperature integer-centered rolling-SD signature is absent. At room temperature, an adaptive SD-based protocol enables selected low-variability conductance states to be captured and retained from several minutes to several hours; a captured state with a mean conductance of 2.036G0 exhibits a relative SD of approximately 0.13% over 60,000 measurements. These results demonstrate that low-variability, integer-centered conductance states can emerge and be retained within a centimeter-scale, macroscopically disordered, non-conjugated polymer−metal system under ambient conditions.