Excitation spectrum in Ni- and Cu-dopedZrTe3
Autor: | Hechang Lei, Cedomir Petrovic, Hyejin Ryu, Leonardo Degiorgi, Xiangde Zhu, C. Mirri, A. Dusza |
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Rok vydání: | 2014 |
Předmět: |
Physics
Superconductivity Condensed matter physics Chalcogenide Plane (geometry) Fermi surface Charge (physics) Condensed Matter Physics Polarization (waves) Electromagnetic radiation Electronic Optical and Magnetic Materials chemistry.chemical_compound chemistry Condensed Matter::Superconductivity Condensed Matter::Strongly Correlated Electrons Excitation |
Zdroj: | Physical Review B. 89 |
ISSN: | 1550-235X 1098-0121 |
DOI: | 10.1103/physrevb.89.035144 |
Popis: | ZeTe${}_{3}$ belongs to the ample class of chainlike chalcogenide charge-density-wave (CDW) materials. Its peculiarity consists in the formation of the CDW condensate at ${T}_{\mathrm{CDW}}$ along the crystallographic directions perpendicular to the $b$-axis, Zr-Zr chains. Ni and Cu intercalation of ZrTe${}_{3}$ leads to the onset of bulk superconductivity at ${T}_{c}l{T}_{\mathrm{CDW}}$, raising questions about the possible coexistence as well as competition between both broken-symmetry ground states. Here, we report on the optical investigation of Ni${}_{0.05}$ZrTe${}_{3}$ and Cu${}_{0.05}$ZrTe${}_{3}$ single crystals performed with electromagnetic radiation polarized along the in-plane crystallographic $a$ and $b$ axes, over a broad spectral range and as a function of temperature. The charge dynamics of the CDW state displays a polarization dependence within the $ab$ plane and gives evidence for a partial gapping of the Fermi surface, which affects almost exclusively the crystallographic direction parallel to the $a$ axis. We provide a complementary analysis of the spectral weight distribution, disentangling its reshuffling in the excitation spectrum across the symmetry-breaking CDW transition. While the superconducting energy gap lies outside our measurable spectral range, we observe nonetheless that the CDW-gap feature persists at $Tl{T}_{c}$. We propose that CDW and superconductivity coexist along the $a$ axis. |
Databáze: | OpenAIRE |
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