Superconductivity of Co-Doped CaKFe4As4 Investigated via Point-Contact Spectroscopy and London Penetration Depth Measurements
Fuente:
arXiv
Salvato in:
| Autori principali: | , , , , , |
|---|---|
| Natura: | Preprint |
| Pubblicazione: |
2024
|
| Soggetti: | |
| Accesso online: | |
| Tags: |
Aggiungi Tag
Nessun Tag, puoi essere il primo ad aggiungerne!!
|
| _version_ | 1866929449661890560 |
|---|---|
| author | Piatti, Erik Torsello, Daniele Breccia, Francesca Tamegai, Tsuyoshi Ghigo, Gianluca Daghero, Dario |
| author_facet | Piatti, Erik Torsello, Daniele Breccia, Francesca Tamegai, Tsuyoshi Ghigo, Gianluca Daghero, Dario |
| contents | The iron-based superconductors (IBSs) of the recently discovered 1144 class, unlike many other IBSs, display superconductivity in their stoichiometric form and are intrinsically hole doped. The effects of chemical substitutions with electron donors are thus particularly interesting to investigate. Here, we study the effect of Co substitution in the Fe site of CaKFe$_4$As$_4$ single crystals on the critical temperature, on the energy gaps, and on the superfluid density by using transport, point-contact Andreev-reflection spectroscopy (PCARS), and London penetration depth measurements. The pristine compound (T$_\mathrm{c}\simeq$ 36 K) shows two isotropic gaps whose amplitudes ($Δ_1$ = 1.4$-$3.9 meV and $Δ_2$ = 5.2$-$8.5 meV) are perfectly compatible with those reported in the literature. Upon Co doping (up to $\approx$7% Co), T$_\mathrm{c}$ decreases down to $\simeq$ 20 K, the spin-vortex-crystal order appears, and the low-temperature superfluid density is gradually suppressed. PCARS and London penetration depth measurements perfectly agree in demonstrating that the nodeless multigap structure is robust upon Co doping, while the gap amplitudes decrease as a function of T$_\mathrm{c}$ in a linear way with almost constant values of the gap ratios 2$Δ_i$/k$_\mathrm{B}$T$_\mathrm{c}$. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2408_02511 |
| institution | arXiv |
| publishDate | 2024 |
| record_format | arxiv |
| spellingShingle | Superconductivity of Co-Doped CaKFe4As4 Investigated via Point-Contact Spectroscopy and London Penetration Depth Measurements Piatti, Erik Torsello, Daniele Breccia, Francesca Tamegai, Tsuyoshi Ghigo, Gianluca Daghero, Dario Superconductivity Mesoscale and Nanoscale Physics Materials Science The iron-based superconductors (IBSs) of the recently discovered 1144 class, unlike many other IBSs, display superconductivity in their stoichiometric form and are intrinsically hole doped. The effects of chemical substitutions with electron donors are thus particularly interesting to investigate. Here, we study the effect of Co substitution in the Fe site of CaKFe$_4$As$_4$ single crystals on the critical temperature, on the energy gaps, and on the superfluid density by using transport, point-contact Andreev-reflection spectroscopy (PCARS), and London penetration depth measurements. The pristine compound (T$_\mathrm{c}\simeq$ 36 K) shows two isotropic gaps whose amplitudes ($Δ_1$ = 1.4$-$3.9 meV and $Δ_2$ = 5.2$-$8.5 meV) are perfectly compatible with those reported in the literature. Upon Co doping (up to $\approx$7% Co), T$_\mathrm{c}$ decreases down to $\simeq$ 20 K, the spin-vortex-crystal order appears, and the low-temperature superfluid density is gradually suppressed. PCARS and London penetration depth measurements perfectly agree in demonstrating that the nodeless multigap structure is robust upon Co doping, while the gap amplitudes decrease as a function of T$_\mathrm{c}$ in a linear way with almost constant values of the gap ratios 2$Δ_i$/k$_\mathrm{B}$T$_\mathrm{c}$. |
| title | Superconductivity of Co-Doped CaKFe4As4 Investigated via Point-Contact Spectroscopy and London Penetration Depth Measurements |
| topic | Superconductivity Mesoscale and Nanoscale Physics Materials Science |
| url | https://arxiv.org/abs/2408.02511 |