We study the low-temperature magnetotransport properties of several highly disordered amorphous indium oxide (a:InO) samples. Simultaneously fabricated devices comprising a two-dimensional (2D) film and 10-mu m-long wires of different widths were measured to investigate the effect of size as we approach the 1D limit, which is around 4 times the correlation length, and happens to be around 100 nm for a:InO. The film and the wires showed magnetic field (B)-induced superconductor to insulator transition (SIT). In the superconducting side, the resistance increased with decrease in wire width, whereas an opposite trend is observed in the insulating side. We find that this effect can be explained in light of charge-vortex duality picture of the SIT. Resistance of the 2D film follows an activated behavior over the temperature (T), whereas, the wires show a crossover from the high-T-activated to a T-independent behavior. At high-temperature regime the wires' resistance follow the film's until they deviate and became independent of T. We find that the temperature at which this deviation occurs evolves with the magnetic field and the width of the wire, which show the effect of finite size on the transport.
- SUPERCONDUCTOR-INSULATOR TRANSITION
- QUANTUM PHASE-TRANSITIONS
- DISORDERED SUPERCONDUCTORS
- 2-DIMENSIONAL LIMIT
- 2D SUPERCONDUCTORS