Magnetic-field-induced 1st order transition to FFLO state at paramagnetic limit in 2D superconductors

Abstract

We have recently reported the first direct calorimetric observation of a magnetic-field-induced first-order phase transition into a high-field FFLO superconducting state at the Clogston-Chandrasekar `Pauli' paramagnetic limit $H_p$ in a 2D superconductor $\kappa -{\text{(BEDT-TTF)}}_2\text{Cu}{\text{(NCS)}}_2$. The high-field state is both higher entropy and strongly paramagnetic, as thermodynamically required for the FFLO state. Here we compare our results with theoretical predictions for the field dependence of the high-field FFLO state in the 2D limit, revealing tentative evidence for transitions between FFLO states of differing order parameter. We also present calorimetric evidence for a 1st order phase transition into the FFLO state for a second 2D organic superconductor: ${\beta }^{\prime \prime }-{\text{(BEDT-TTF)}}_2{\text{SF}}_5{\text{(CH)}}_2{\text{(CF)}}_2{\text{(SO)}}_3$.

Proceedings of the 28th International Conference on Low Temperature Physics (LT28 August 2017), to be published

References in corpus (5)

• Fulde-Ferrell-Larkin-Ovchinnikov State in Heavy Fermion Superconductors
• Calorimetric Evidence for a Fulde-Ferrell-Larkin-Ovchinnikov Superconducting State in the Layered Organic Superconductor κ$-(BEDT-TTF)$_2$Cu(NCS)$_2$
• Evidence of Andreev bound states as a hallmark of the FFLO phase in $\kappa$-(BEDT-TTF)${}_2$Cu(NCS)${}_2$
• Upper critical field study in the organic superconductor ${\beta }^{\prime \prime }$-(ET)${}_2$SF${}_5$CH${}_2$CF${}_2$SO${}_3$ : Possibility of Fulde-Ferrell-Larkin-Ovchinnikov state
• Calorimetric Measurements of Magnetic-Field-Induced Inhomogeneous Superconductivity Above The Paramagnetic Limit

Cited by in corpus (2)

• Orbital-Induced Crossover of the Fulde-Ferrell-Larkin-Ovchinnikov Phase into Abrikosov-like States
• Temperature dependent anisotropy and two-band superconductivity revealed by lower critical field in organic superconductor $\kappa$-(BEDT-TTF)${}_2$Cu[N(CN)${}_2$]Br