Berlin 2018 – wissenschaftliches Programm
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TT: Fachverband Tiefe Temperaturen
TT 3: Superconductivity: Properties and Electronic Structure I
TT 3.2: Vortrag
Montag, 12. März 2018, 09:45–10:00, H 0110
Strong coupling superconductivity in the aperiodic high-pressure phase of bismuth — •Konstantin Semeniuk1, Philip Brown1, Stephen Hodgson1, Diandian Wang1, Bartomeu Monserrat2,1, Chris Pickard3,4, and Malte Grosche1 — 1Cavendish Laboratory, University of Cambridge, UK — 2Dept. of Physics and Astronomy, Rutgers University, Piscataway, USA — 3Dept. of Materials Science, University of Cambridge, UK — 4Advanced Institute for Materials Research, Tohoku University, Japan
Application of hydrostatic pressure to elemental materials surprisingly often leads to the emergence of structurally complex phases [1]. Examples include aperiodic structures consisting of two incommensurate sublattices, seen in high pressure phases of bismuth, antimony, barium and other elemental metals. Aside from crystallographic characterisation, not many experiments have been conducted to explore the electronic and vibrational properties of these systems. We examine the incommensurate host-guest structure of high pressure bismuth, Bi-III, which superconducts below 7 K and has an anomalously large gradient of resistivity against temperature below 50 K. We attribute its properties to the existence of sliding modes, or phasons, which cause enhanced electron-phonon scattering at low temperature and boost electron-phonon coupling constant to λ≃2.8, indicating unusually strong coupling superconductivity for an element.
M. I. McMahon, R. J. Nelmes, Chem. Soc. Rev. 35(2006)943.