Abstract
In the following, a brief overview on the recently found robust experimental evidence for the existence of the Fulde–Ferrell–Larkin–Ovchinnikov (FFLO) state in layered organic superconductors is given. These electronically quasi-two-dimensional (2D) clean-limit superconductors are ideally suited for observing FFLO states. Applying a magnetic field parallel to the layers suppresses orbital effects and superconductivity is observed beyond the Pauli paramagnetic limit. Both, thermodynamic as well as microscopic experimental data show the existence of an additional high-field low-temperature superconducting state having a one-dimensionally modulated order parameter.
Highlights
IntroductionSuperconductivity is destroyed at high magnetic fields. For spin-singlet pairing, the highest field where this phase change can occur is at the Pauli paramagnetic limit when the Zeeman energy of the itinerant electrons becomes larger than the condensation energy [1,2]
In most cases, superconductivity is destroyed at high magnetic fields
The first thermodynamic evidence for the appearance of an FFLO state was found for the organic superconductor κ-(BEDT-TTF)2 Cu(NCS)2 by use of specific-heat measurements [37]
Summary
Superconductivity is destroyed at high magnetic fields. For spin-singlet pairing, the highest field where this phase change can occur is at the Pauli paramagnetic limit when the Zeeman energy of the itinerant electrons becomes larger than the condensation energy [1,2]. The mean free path of the charge carriers needs to be larger than the coherence length, i.e., clean-limit superconductors are needed [7,8,9] For the latter point, some theory works suggest that FFLO phases may survive even with some disorder [10,11,12,13]. It is worthwhile to mention that the notion of FFLO states is of much broader importance than for superconductivity in condensed matter These exotic states are predicted to exist in general in polarized, spin-imbalanced Fermi systems, such as ultra-cold atomic gases [19], nuclear matter, and dense quark matter [20].
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
