Zeeman driven superconductor insulator transition in strongly disordered MoC film. STM and transport studies in transverse magnetic field

Abstract

Superconductor insulator transition in transverse magnetic field is studied in the highly disordered MoC film with the product of the Fermi momentum and the mean free path $k_F\ast l$ close to unity. Surprisingly, the Zeeman paramagnetic effects dominate over orbital coupling on both sides of the transition. In superconducting state it is evidenced by a high upper critical magnetic field $B_{c2}$, by its square root dependence on temperature, as well as by the Zeeman splitting of the quasiparticle density of states (DOS) measured by scanning tunneling microscopy. At $B_{c2}$ a logarithmic anomaly in DOS is observed. This anomaly is further enhanced in increasing magnetic field, which is explained by the Zeeman splitting of the Altshuler-Aronov DOS driving the system into a more insulating or resistive state. Spin dependent Altshuler-Aronov correction is also needed to explain the transport behavior above $B_{c2}$.

arXiv commentEquation (1) is corrected in this version. See the Erratum in PRB

References in corpus (11)

• Fulde-Ferrell-Larkin-Ovchinnikov State in Heavy Fermion Superconductors
• Disorder-Induced Inhomogeneities of the Superconducting State Close to the Superconductor-Insulator Transition
• Anomalous metals -- failed superconductors
• Theoretical Studies of Superconductor-Insulator Transitions
• Quantum coherence across bosonic superconductor-anomalous metal-insulator transitions
• Superconducting fluctuations at low temperature
• Microscopic interpretation of the Dynes formula for the tunneling density of states
• Fermionic scenario for the destruction of superconductivity in ultrathin MoC films evidenced by STM measurements
• Observation of quantum corrections to conductivity up to optical frequencies
• On the origin of in-gap states in homogeneously disordered ultrathin films. MoC case
• Robust pseudogap across the magnetic field driven superconductor to insulator-like transition in strongly disordered NbN films

Cited by in corpus (5)

• Size dependent nature of the magnetic-field driven superconductor-to-insulator quantum-phase transitions
• Magnetic field induced transition from a vortex liquid to Bose metal in ultrathin a-MoGe thin film
• Detailed Analysis of the Superconducting Gap with Dynes Pair-Breaking Scattering
• Model-independent determination of the gap function of nearly localized superconductors
• Advanced approach of superconducting gap function extraction from tunneling experiments