Interplay between superconducting fluctuations and weak localization in disordered TiN thin films.

Area of Science:

• Condensed Matter Physics
• Materials Science
• Quantum Phenomena

Background:

• Understanding quantum effects in low-dimensional superconductors is crucial.
• Superconducting fluctuations (SFs) and weak localization (WL) are key phenomena affecting electronic properties.
• Their interplay in two-dimensional (2D) systems requires detailed investigation.

Purpose of the Study:

• To investigate the interplay between SFs and WL in 2D disordered superconducting TiN thin films.
• To analyze temperature-dependent resistance and magnetoresistance to understand these quantum contributions.
• To determine the temperature-driven crossover in dominance between SFs and WL.

Main Methods:

• Temperature-dependent resistance (R(T)) measurements.
• Magnetoresistance (MR) measurements at various temperatures and magnetic fields.
• Analysis using quantum corrections to conductivity (QCC) theory.

Main Results:

• Observed coexistence of positive MR (SF-mediated) and negative MR (WL-led) in specific temperature and magnetic field ranges.
• Demonstrated a crossover from positive to negative MR with increasing temperature, coinciding with a resistance peak temperature (Tmax).
• Quantified the temperature-dependent dominance: SFs prevail just above Tc, WL dominates at Tmax, with comparable contributions in between.

Conclusions:

• Weak localization can fully account for the observed negative magnetoresistance.
• The study provides a method to monitor the dominance of SFs and WL contributions in 2D superconductors.
• This approach is applicable to other 2D superconductors where both SFs and WL are significant.