Anomalously high value of Coulomb pseudopotential for the H5S2 superconductor

Kostrzewa, M.; Szczȩśniak, R.; Kalaga, J. K.; Wrona, I. A.

doi:10.1038/s41598-018-30391-z

Cited by 12 publications

(8 citation statements)

References 60 publications

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“…The report of high-temperature superconductivity in dense H 2 S has galvanized studies of the high-pressure sulfurhydrogen system [1], yet the composition and nature of bonding in the superconducting phase remain disputed [2][3][4][5][6][7][8][9][10][11].…”

Section: Introductionmentioning

confidence: 99%

Properties and phase diagram of (H2S)2H2

et al. 2020

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By combining hydrogen and sulfur within diamond-anvil cells we synthesize (H 2 S) 2 H 2 at 5 GPa and 373 K. Through a series of Raman spectroscopy, infrared spectroscopy, and synchrotron x-ray diffraction experiments we have constrained the phase diagram of (H 2 S) 2 H 2 within a wide P-T range. On compression we observe the phase transition sequence of I-II-II-III, where II is a previously unreported phase; at room temperature this sequence spans from 5 to 47 GPa, while the application of low temperatures stabilizes this sequence to 127 GPa (< 80 K). Above these pressures we propose that phase III of (H 2 S) 2 H 2 transforms to a nonmolecular H 3 S network. Our Raman and infrared measurements indicate that the transition from (H 2 S) 2 H 2 to H 3 S is reversible at room temperature. X-ray diffraction reveals that the symmetry of the underlying S lattice of (H 2 S) 2 H 2 and H 3 S is retained along this compression path up to at least 135 GPa.

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Section: Introductionmentioning

confidence: 99%

Properties and phase diagram of (H2S)2H2

et al. 2020

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“…It is worth emphasizing the fact that discussed equations are the same in form as equations that would be derived in local approximation [43][44][45][46][47][48], where eigen energies are averaged over the entire Brillouin zone, not just the Fermi surface. Thus, the used approximation seems to be reasonable since the phonon-induced superconducting state in hydrogen containing systems is highly isotropic [49], [50]. It is also worth noting that the literature gives the form of Eliashberg equations that take into account the vertex corrections explicitly dependent on wave vector k [51,52].…”

Section: Eliashberg Formalism Including the Vertex Correctionmentioning

confidence: 99%

“…( 11) was originally used to investigate the properties of superconducting state induced in lead [27]. Later, the discussed model was successfully applied to analysis of superconducting state in hydrogen-rich systems such as H 5 S 2 [50], PH 3 and H 3 S [49]. In these compounds, the critical temperature is equal to: 36 K, 80 K, and 200 K for H 5 S 2 , PH 3 , and H 3 S, respectively.…”

Section: Eliashberg Formalism Including the Vertex Correctionmentioning

confidence: 99%

Carbonaceous sulfur hydride system: the strong-coupled room-temperature superconductor with a low value of Ginzburg-Landau parameter

Wrona,

Kostrzewa,

Krok

et al. 2021

Preprint

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The superconducting state in Carbonaceous Sulfur Hydride (C-S-H) system is characterized by the record-high critical temperature of 288 K experimentally observed at ∼267 GPa. Herein, we determined the properties of the C-S-H superconducting phase within the scope of both classical Eliashberg equations (CEE) and the Eliashberg equations with vertex corrections (VCEE). We took into account the scenarios pertinent to either the intermediate or the high value of electron-phonon coupling constant (λ ∼ 0.75 or λ ∼ 3.3, respectively). The scenario for the intermediate value, however, cannot be actually realized due to the anomally high value of logarithmic phonon frequency (ω ln /kB = 7150 K) it would require. On the other hand, we found it possible to reproduce correctly the value of TC and other thermodynamic quantities in the case of strong coupling. However, the vertex corrections lower the order parameter values within the range from ∼ 50 K to ∼ 275 K. For the upper critical field HC2 ∼ 27 T, the Ginzburg-Landau parameter κ is of the order of 1.7. This correlates well with the sharp drop of resistance observed by Hirsch and Marsiglio at the critical temperature. The strong-coupling scenario for C-S-H system is also suggested by the high values of λ estimated for H3S (λ ∼ 2.1, κ ∼ 1.5), LaH10 (λ ∼ 2.8-3.9, κ ∼ 1.6), and YH6 (λ ∼ 1.7, κ ∼ 1.3) compounds.

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“…Also, Freericks' equations have been recently successfully used to analyze the superconducting state with high critical temperature values in compounds such as PH 3 (T C ≈ 80 K), H 3 S (T C ≈ 200 K) [75], and H 2 S (T C ≈ 35 K) [76].…”

Section: Theoretical Modelmentioning

confidence: 99%

Nonadiabatic superconductivity in a Li-intercalated hexagonal boron nitride bilayer

Szewczyk¹,

Domagalska²,

Durajski³

et al. 2020

Beilstein J. Nanotechnol.

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When considering a Li-intercalated hexagonal boron nitride bilayer (Li-hBN), the vertex corrections of electron–phonon interaction cannot be omitted. This is evidenced by the very high value of the ratio λωD/εF ≈ 0.46, where λ is the electron–phonon coupling constant, ωD is the Debye frequency, and εF represents the Fermi energy. Due to nonadiabatic effects, the phonon–induced superconducting state in Li-hBN is characterized by much lower values of the critical temperature (T LOVC C ∈ {19.1, 15.5, 11.8} K, for μ* ∈ {0.1, 0.14, 0.2}, respectively) than would result from calculations not taking this effect into account (T ME C∈ {31.9, 26.9, 21} K). From the technological point of view, the low value of T C limits the possible applications of Li-hBN. The calculations were carried out under the classic Migdal–Eliashberg formalism (ME) and the Eliashberg theory with lowest-order vertex corrections (LOVC). We show that the vertex corrections of higher order (λ3) lower the value of T LOVC C by a few percent.

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Anomalously high value of Coulomb pseudopotential for the H5S2 superconductor

Cited by 12 publications

References 60 publications

Properties and phase diagram of (H2S)2H2

Properties and phase diagram of (H2S)2H2

Carbonaceous sulfur hydride system: the strong-coupled room-temperature superconductor with a low value of Ginzburg-Landau parameter

Nonadiabatic superconductivity in a Li-intercalated hexagonal boron nitride bilayer

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