Suppression of superconductivity in disordered interacting wires

Area of Science:

• Condensed matter physics
• Quantum phenomena

Background:

• Superconductivity is a quantum mechanical phenomenon where electrical resistance vanishes.
• Disordered systems and thermal fluctuations can suppress superconductivity.
• The Ginzburg-Landau theory is a common approach to describe superconductivity.

Purpose of the Study:

• To investigate superconductivity suppression in disordered wires due to thermal fluctuations.
• To identify and characterize novel fluctuation mechanisms beyond the Ginzburg-Landau framework.
• To quantify the contribution of these fluctuations to wire resistivity and magnetoresistance.

Main Methods:

• Utilizing the replica nonlinear sigma-model (NLsigmaM) to study the system.
• Analyzing saddle points within the NLsigmaM to describe new fluctuation types.
• Evaluating the contribution of these fluctuations to resistivity with exponential accuracy.

Main Results:

• Identified a new type of fluctuation, distinct from thermal phase slips, that leads to finite resistivity.
• These fluctuations are described by saddle points in the NLsigmaM.
• The contribution of these fluctuations to resistivity was calculated with exponential accuracy.
• Observed negative magnetoresistance associated with these fluctuations.

Conclusions:

• The study reveals a novel mechanism for superconductivity suppression in disordered wires.
• This mechanism, involving NLsigmaM saddle points, goes beyond the standard Ginzburg-Landau approach.
• The findings have implications for understanding and predicting the behavior of superconducting materials in the presence of thermal fluctuations and magnetic fields.