Superconductivity of In/Mo narrow wires fabricated using focused Ga-ion beam

• Qquasi-1D In/Mo specimens on SiO/Si were fabricated by the FIB milling with Ga ions.
• The q-1D wire affected by Ga-ion irradiation showed superconductivity with Tc0>5 K.
• The R–T data good agreement with thermal activation phase-slip model.

By using a focused-ion-beam (FIB) method with Ga ions, we prepared quasi-one-dimensional (q-1D) In/Mo specimens with widths of ≈200nm and ≈500nm from two dimensional (2D) films deposited on a SiO2/Si substrate. We observed the superconducting transition of q-1D In/Mo, whose transition temperature Tc is higher than Tc≈3.6K of a 2D In/Mo specimen on a glass substrate. For specimens fabricated using the FIB method, the element distributions analyzed by energy dispersive x-ray spectroscopy reveal Ga invasion into the q-1D In/Mo region. The gradually changing resistance of q-1D In/Mo at temperatures below Tc can be well explained by the thermal activation phase-slip model with Tc=5.1K and coherence length ξ(0)≈9.5nm.