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Pressure and high-Tc superconductivity in sulfur hydrides.

Title: Pressure and high-Tc superconductivity in sulfur hydrides.
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Name(s): Gor'kov, Lev P, author
Kresin, Vladimir Z, author
Type of Resource: text
Genre: Journal Article
Text
Date Issued: 2016-05-11
Physical Form: computer
online resource
Extent: 1 online resource
Language(s): English
Abstract/Description: The paper discusses fundamentals of record-TC superconductivity discovered under high pressure in sulfur hydride. The rapid increase of TC with pressure in the vicinity of Pcr ≈ 123GPa is interpreted as the fingerprint of a first-order structural transition. Based on the cubic symmetry of the high-TC phase, it is argued that the lower-TC phase has a different periodicity, possibly related to an instability with a commensurate structural vector. In addition to the acoustic branches, the phonon spectrum of H3S contains hydrogen modes with much higher frequencies. Because of the complex spectrum, usual methods of calculating TC are here inapplicable. A modified approach is formulated and shown to provide realistic values for TC and to determine the relative contributions of optical and acoustic branches. The isotope effect (change of TC upon Deuterium for Hydrogen substitution) originates from high frequency phonons and differs in the two phases. The decrease of TC following its maximum in the high-TC phase is a sign of intermixing with pairing at hole-like pockets which arise in the energy spectrum of the cubic phase at the structural transition. On-pockets pairing leads to the appearance of a second gap and is remarkable for its non-adiabatic regime: hydrogen mode frequencies are comparable to the Fermi energy.
Identifier: FSU_pmch_27167334 (IID), 10.1038/srep25608 (DOI), PMC4863257 (PMCID), 27167334 (RID), 27167334 (EID), srep25608 (PII)
Publication Note: This NIH-funded author manuscript originally appeared in PubMed Central at https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4863257.
Persistent Link to This Record: http://purl.flvc.org/fsu/fd/FSU_pmch_27167334
Host Institution: FSU
Is Part Of: Scientific reports.
2045-2322
Issue: vol. 6

Choose the citation style.
Gor'kov, L. P., & Kresin, V. Z. (2016). Pressure and high-Tc superconductivity in sulfur hydrides. Scientific Reports. Retrieved from http://purl.flvc.org/fsu/fd/FSU_pmch_27167334