Nonadiabatic breakdown and pairing in high-Tc compounds

Pietronero, L.; Cappelluti, E.

doi:10.1063/1.2199434

Cited by 5 publications

(5 citation statements)

References 132 publications

(241 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…It means that the non-adiabatic effects appear to complement depairing Coulomb interaction. This behavior is potentially related to the structure of the vertex corrections upon the induction of the superconducting state, when superconducting gap is enhancing their negative part [21,34]. As a consequence, the effective electronphonon pairing is smaller at T 0 than T C resulting in the observed here reduction of the Δ parameter in the framework of the N-E equations.…”

Section: (B) For Graphical Representation)mentioning

confidence: 99%

“…This is to say, the non-adiabatic channels open up in the electronphonon pairing and the resulting effects start to influence the corresponding superconducting phase [18,19]. According to Pietronero et al, these effects may have positive or negative impact and can be qualitatively related to the vertex corrections of the electron-phonon interaction [18][19][20][21]. Namely, when the corresponding vertex function takes positive values it results in an enhancement of the superconducting properties while negative values lead to their reduction [21].…”

mentioning

confidence: 99%

“…According to Pietronero et al, these effects may have positive or negative impact and can be qualitatively related to the vertex corrections of the electron-phonon interaction [18][19][20][21]. Namely, when the corresponding vertex function takes positive values it results in an enhancement of the superconducting properties while negative values lead to their reduction [21]. Hence, the proper characterization of these effects should be of great importance to the further understanding of superconductivity in the modified graphene.…”

mentioning

confidence: 99%

“…The main purpose of this analysis is to identify such effects in order to provide potential routes toward higher T C values in the discussed structures. In particular, this is done within the perturbationapproach that includes the lowest level vertex corrections [18][19][20][21] and is employed here in the framework of the Eliashberg equations [16,22]. As a case study we investigate here the superconducting phase that has been suggested to exist in the nitrogendoped graphene (h-CN), i.e., the structure equivalent to the electron-doped graphene.…”

mentioning

confidence: 99%

See 3 more Smart Citations

Non-adiabatic superconductivity in the electron-doped graphene

Szczęśniak¹,

Drzazga-Szczęśniak²

2021

EPL

View full text Add to dashboard Cite

In the present study, we investigate the impact of the non-adiabatic effects on the superconducting state in the electron-doped graphene. In particular, by using the Eliashberg formalism we analyze the case scenario of the nitrogen-doped graphene, showing that the non-adiabatic effects complement electron-electron interaction and notably reduce (up to ∼ 40%) pivotal thermodynamic properties, such as: the critical temperature, the superconducting gap and their characteristic ratio. Interestingly, the influence of the non-adiabatic effects is found to rise together with the increase of the depairing Coulomb interaction. These observations are elucidated based on the structure of the vertex corrections to the electron-phonon interaction. As a result, we draw a direction for the future research in the field of the two-dimensional non-adiabatic superconductivity.

show abstract

Section: (B) For Graphical Representation)mentioning

confidence: 99%

mentioning

confidence: 99%

mentioning

confidence: 99%

mentioning

confidence: 99%

See 2 more Smart Citations

Non-adiabatic superconductivity in the electron-doped graphene

Szczęśniak¹,

Drzazga-Szczęśniak²

2021

EPL

View full text Add to dashboard Cite

show abstract

“…Such behavior results in nonadiabatic effects strongly influencing the superconducting phase [14,15]. As suggested in [14,16], non-adiabatic effects may have nontrivial impact on the electron-phonon interaction, as can be observed from the behavior of the order parameter. For example, the proper characterization of these effects in graphene has recently been described for the electron-doped graphene structures in [8].…”

Section: Introductionmentioning

confidence: 93%

Superconducting Energy Gap in Hole-Doped Graphene Beyond the Migdal's Theory

Kaczmarek

Drzazga-Szczęśniak

2023

Acta Phys. Pol. A

View full text Add to dashboard Cite

In this work, we analyze the impact of non-adiabatic effects on the superconducting energy gap in hole-doped graphene. By using the Eliashberg formalism beyond Migdal's theorem, we present that non-adiabatic effects strongly influence the superconducting energy gap in the exemplary boron-doped graphene. In particular, non-adiabatic effects, as represented by the first-order vertex corrections to the electron-phonon interaction, supplement the Coulomb depairing correlations and suppress the superconducting state. In summary, the obtained results confirm previous studies on superconductivity in two-dimensional materials and show that the corresponding superconducting phase may be notably affected by non-adiabatic effects.

show abstract

Electronic Correlations Stabilize the Antiferromagnetic Mott State inCs3C60

Giovannetti¹,

Capone²

2012

Phys. Rev. Lett.

View full text Add to dashboard Cite

Cs3C60 in the A15 structure is an antiferromagnet at ambient pressure in contrast with other superconducting trivalent fullerides. Superconductivity is recovered under pressure and reaches the highest critical temperature of the family. Comparing density-functional calculations with generalized gradient approximation to the hybrid functional HSE, which includes a suitable component of exchange, we establish that the antiferromagnetic state of Cs3C60 is not due to a Slater mechanism, and it is stabilized by electron correlation. HSE also reproduces the pressure-driven metalization. Our findings corroborate previous analyses suggesting that the properties of this compound can be understood as the result of the interplay between electron correlations and Jahn-Teller electronphonon interaction. [5]. The unavoidable question about the "pairing glue" in the fullerides seems to have an answer at least for the standard members of the family, like K 3 C 60 or Rb 3 C 60 . For these compounds there is convincing evidence of an electronphonon driven superconductivity, in which Jahn-Tellercoupled intramolecular vibrations play the main role [6]. Nonetheless, the anomalous properties of "expanded" fullerides with large intermolecular distance, like ammoniated compounds [7] and most notably Cs 3 C 60 suggest that labeling these materials as standard superconductors described by the Bardeen-Cooper-Schrieffer (BCS) theory is at least hazardous.The anomalies are particularly clear in Cs 3 C 60 , in which the large Cs ions increase the lattice spacing in comparison with K-and Rb-doping. This compound is synthesized in two different crystal structure, the fcc which is common to most doped fullerides and a A15 structure, with a bipartite lattice [8]. A15 Cs3C 60 at ambient pressure is an antiferromagnetic (AFM) insulator with T N = 46K and a spin-1/2 moment at each molecule [9], as opposed to K 3 C 60 and Rb 3 C 60 , which are superconductors in the same conditions. A superconducting state is recovered under external pressure of around 4Kbar. Even more interestingly, the critical temperature has a bell-shaped behavior as a function of pressure, with a maximum of 38K at P = 7KBar. The proximity between superconductivity and antiferromagnetism and the existence of a maximum remind of the phase diagram of several exotic superconductors, ranging from the high-temperature copper-oxides to heavy fermion materials, even if in the present case the bell-shaped curve is a function of lattice spacing instead of doping. However, since the phase diagrams of these latter materials are believed to be dominated by strong electron-electron correlations and by the proximity to a Mott insulator, this similarity suggests that also the physics of Cs 3 C 60 can be understood in the same framework.The role of electron-electron correlations has been underlined well before Cs 3 C 60 was known on the basis of estimates of the Coulomb interaction and the bandwidth [10,11] In this light, the synthesis of Cs 3 C 60 provides a system in which the correlation ef...

show abstract

Nonadiabatic breakdown and pairing in high-Tc compounds

Cited by 5 publications

References 132 publications

Non-adiabatic superconductivity in the electron-doped graphene

Non-adiabatic superconductivity in the electron-doped graphene

Superconducting Energy Gap in Hole-Doped Graphene Beyond the Migdal's Theory

Electronic Correlations Stabilize the Antiferromagnetic Mott State inCs3C60

Contact Info

Product

Resources

About