2007/05/14 by N. Shah, Nayana Shah, A. V. Lopatin
Physics and Astronomy · #Physics of Superconductivity and Magnetism #Quantum and electron transport phenomena #Rare-earth and actinide compounds #cond-mat.mes-hall #cond-mat.supr-con
paper · pdf · doi:10.1103/physrevb.76.094511
published as Phys. Rev. B 76, 094511 (2007) · 20 pages, 9 figures
arxiv created 2007/05/14 · openalex publication_date 2007/09/14 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
A microscopic analysis of the superconducting quantum critical point realized via a pair-breaking quantum phase transition is presented. Finite-temperature crossovers are derived for the electrical conductivity, which is a key probe of superconducting fluctuations. By using the diagrammatic formalism for disordered systems, we are able to incorporate the interplay between fluctuating Cooper pairs and electrons, that is outside the scope of a time-dependent Ginzburg-Landau or effective bosonic action formalism. It is essential to go beyond the standard approximation in order to capture the zero-temperature correction which results purely from the (dynamic) quantum fluctuations and dictates the behavior of the conductivity in an entire low-temperature quantum regime. All dynamic contributions are of the same order and conspire to add up to a negative total, thereby inhibiting the conductivity as a result of superconducting fluctuations. On the contrary, the classical and the intermediate regimes are dominated by the positive bosonic channel. Our theory is applicable in one, two, and three dimensions and is relevant for experiments on superconducting nanowires, doubly connected cylinders, thin films, and bulk in the presence of magnetic impurities, magnetic field, or other pair breakers. A window of nonmonotonic behavior is predicted to exist as either the temperature or the pair-breaking parameter is swept.