Superconductor-insulator quantum phase transition

Abstract

The current understanding of the superconductor-insulator transition is discussed level by level in a cyclic spiral-like manner. At the first level, physical phenomena and processes are discussed which, while of no formal relevance to the topic of transitions, are important for their implementation and observation; these include superconductivity in low electron density materials, transport and magnetoresistance in superconducting island films and in highly resistive granular materials with superconducting grains, and the Berezinskii-Kosterlitz-Thouless transition. The second level discusses and summarizes results from various microscopic approaches to the problem, whether based on the Bardeen-Cooper-Schrieffer theory (the disorder-induced reduction in the superconducting transition temperature; the key role of Coulomb blockade in high-resistance granular superconductors; superconducting fluctuations in a strong magnetic field) or on the theory of the Bose-Einstein condensation. A special discussion is given to phenomenological scaling theories. Experimental investigations, primarily transport measurements, make the contents of the third level and are for convenience classified by the type of material used (ultrathin films, variable composition materials, high-temperature superconductors, superconductor-poor metal transitions). As a separate topic, data on nonlinear phenomena near the superconductor-insulator transition are presented. At the final, summarizing, level the basic aspects of the problem are enumerated again to identify where further research is needed and how this research can be carried out. Some relatively new results, potentially of key importance in resolving the remaining problems, are also discussed.

Review article, 57 pages

Cited by in corpus (19)

• Discovery of two-dimensional anisotropic superconductivity at KTaO${}_3$ (111) interfaces
• Two-dimensional superconductivity at the surfaces of KTaO3 gated with ionic liquid
• Single and two-particle energy gaps across the disorder-driven superconductor-insulator transition
• Superconducting, Insulating, and Anomalous Metallic Regimes in a Gated Two-Dimensional Semiconductor-Superconductor Array
• Extreme Sensitivity of the Superconducting State in Thin Films
• Two-stage magnetic-field-tuned superconductor-insulator transition in underdoped La${}_{2-x}$Sr${}_x$CuO${}_4$
• Level statistics of disordered spin-1/2 systems and its implications for materials with localized Cooper pairs
• Fermionic scenario for the destruction of superconductivity in ultrathin MoC films evidenced by STM measurements
• Direct Observation of Fragmentation in a Disordered, Strongly Interacting Fermi Gas
• Vortex phase diagram and the normal state of cuprates with charge and spin orders
• Superconductivity in single-crystalline, aluminum- and gallium-hyperdoped germanium
• Local density of states and its mesoscopic fluctuations near the transition to a superconducting state in disordered systems
• Thermal properties of NbN single-photon detectors
• Two-particle spectral function for disordered s-wave superconductors: local maps and collective modes
• Sequential superconductor-Bose insulator-Fermi insulator phase transitions in two-dimensional a-WSi
• Continuous and reversible tuning of the disorder-driven superconductor-insulator transition in bilayer graphene
• Crystallization in Three-Dimensions: Defect-Driven Topological Ordering and the Role of Geometrical Frustration
• Energy-level statistics in strongly disordered systems with power-law hopping
• Superconducting phase transition in inhomogeneous chains of superconducting islands