Superconductivity of the FeSe/SrTiO3 Interface in the View of BCS-BEC Crossover
arXiv:1908.11126 · doi:10.1088/0256-307X/36/10/107404
Abstract
In paired Fermi systems, strong many-body effects exhibit in the crossover regime between the Bardeen-Cooper-Schrieffer (BCS) and the Bose-Einstein condensation (BEC) limits. The concept of the BCS-BEC crossover, which is studied intensively in the research field of cold atoms, has been extended to condensed matters. Here, by analyzing the typical superconductors within the BCS-BEC phase diagram, we find that FeSe-based superconductors are prone to shift their positions in the BCS-BEC crossover regime by charge doping or substrate substitution, since their Fermi energies and the superconducting gap sizes are comparable. Especially at the interface of a single-layer FeSe on SrTiO3 substrate, the superconductivity is relocated closer to the crossover unitary than other doped FeSe-based materials, indicating that the pairing interaction is effectively modulated. We further show that hole-doping can drive the interfacial system into the phase with possible pre-paired electrons, demonstrating its flexible tunability within the BCS-BEC crossover regime.
arXiv comment15 pages, 3 figures, supplementary materials attached
References in corpus (34)
- Feshbach Resonances in Ultracold Gases
- Interface induced high temperature superconductivity in single unit-cell FeSe films on SrTiO3
- BCS-BEC Crossover: From High Temperature Superconductors to Ultracold Superfluids
- Revealing the Superfluid Lambda Transition in the Universal Thermodynamics of a Unitary Fermi Gas
- Interfacial mode coupling as the origin of the enhancement of Tc in FeSe films on SrTiO3
- Interface-induced superconductivity and strain-dependent spin density wave in FeSe/SrTiO3 thin films
- Electronic Origin of High Temperature Superconductivity in Single-Layer FeSe Superconductor
- Heavily electron-doped electronic structure and isotropic superconducting gap in AxFe2Se2 (A=K,Cs)
- Field-induced superconducting phase of FeSe in the BCS-BEC cross-over
- Observation of pseudogap behavior in a strongly interacting Fermi gas
- Direct observation of high temperature superconductivity in one-unit-cell FeSe films
- BCS-BEC Crossover and the Unitary Fermi Gas
- Strong Interplay between Stripe Spin Fluctuations, Nematicity and Superconductivity in FeSe
- Critical role of substrate in the high temperature superconductivity of single layer FeSe on Nb:BaTiO
- Determination of the Superfluid Gap in Atomic Fermi Gases by Quasiparticle Spectroscopy
- Bose-Einstein to BCS Crossover Picture for High-T_c Cuprates
- Shallow pockets and very strong coupling superconductivity in FeSe_xTe_1-x
- Surface electronic structure and isotropic superconducting gap in (LiFe)OHFeSe
- Universal Substrate Effect on the Superconductivity of FeSe Monolayer Films
- High-temperature superconductivity in single-unit-cell FeSe films on anatase TiO2(001)
- Origin of charge transfer and enhanced electron-phonon coupling in single unit-cell FeSe films on SrTiO3
- The Role of SrTiO3 Phonon Penetrating into thin FeSe Films in the Enhancement of Superconductivity
- Superconductivity in an electron band just above the Fermi level: possible route to BCS-BEC superconductivity
- Condensation, excitation, pairing, and superfluid density in high- superconductors: magnetic resonance mode as a roton analogue and a possible spin-mediated pairing
- Dynamic interfacial polaron enhanced superconductivity of FeSe/SrTiO3
- Quantum vortex core and missing pseudogap in the multi-band BCS-BEC-crossover superconductor FeSe
- Conformity of spin fluctuations in alkali-metal iron selenide superconductors inferred from the observation of a magnetic resonant mode in K(x)Fe(2-y)Se(2)
- Structure of spin excitations in heavily electron-doped Li0.8Fe0.2ODFeSe superconductors
- Lattice Dynamics of Ultrathin FeSe Films on SrTiO3
- Detection of bosonic mode as a signature of magnetic excitation in one unit cell FeSe on SrTiO3
- Quasiparticle Excitations in the Superconducting State of FeSe Probed by Thermal Hall Conductivity in the Vicinity of the BCS-BEC Crossover
- The Emergence of Superconductivity in Heavy Electron Materials
- Superconducting fluctuation in FeSe investigated by precise torque magnetometry
- Superconducting transition of FeSe/SrTiO3 induced by adsorption of semiconducting organic molecules