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Z$_{3}$-vestigial nematic order due to superconducting fluctuations in the doped topological insulators Nb$_{x}$Bi$_{2}$Se$_{3}$ and Cu$_{x}$Bi$_{2}$Se$_{3}$

Cho, Chang-woo; Shen, Junying; Lyu, Jian; Atanov, Omargeldi; Chen, Qianxue; Lee, Seng Huat; Hor, Yew San; Gawryluk, Dariusz Jakub; Pomjakushina, Ekaterina; Bartkowiak, Marek; Hecker, Matthias; Schmalian, Jörg; Lortz, Rolf

A state of matter with a multi-component order parameter can give rise to vestigial order. In the vestigial phase, the primary order is only partially melted, leaving a remaining symmetry breaking behind, an effect driven by strong classical or quantum fluctuations. Vestigial states due to primary spin and charge-density-wave order have been discussed in iron-based and cuprate materials. Here we present the observation of a partially melted superconductivity in which pairing fluctuations condense at a separate phase transition and form a nematic state with broken Z$_{3}$, i.e., three-state Potts-model symmetry. Thermal expansion, specific heat and magnetization measurements of the doped topological insulators Nb$_{x}$Bi$_{2}$Se$_{3}$ and Cu$_{x}$Bi$_{2}$Se$_{3}$ reveal that this symmetry breaking occurs at T$_{nem}$≃3.8K above T$_{c}$≃3.25K, along with an onset of superconducting fluctuations. Thus, before Cooper pairs establish long-range coherence at T$_{c}$, they fluctuate in a way that breaks the rotational invariance at T$_{nem}$ and induces a crystalline distortion.

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Verlagsausgabe §
DOI: 10.5445/IR/1000120275
Veröffentlicht am 27.07.2020
Cover der Publikation
Zugehörige Institution(en) am KIT Institut für Theorie der Kondensierten Materie (TKM)
Institut für Quantenmaterialien und -technologien (IQMT)
Publikationstyp Zeitschriftenaufsatz
Publikationsmonat/-jahr 12.2020
Sprache Englisch
Identifikator ISSN: 2041-1723
KITopen-ID: 1000120275
HGF-Programm 43.21.01 (POF III, LK 01)
Quantum Correlations in Condensed Matter
Erschienen in Nature Communications
Band 11
Heft 1
Seiten Art. Nr.: 3056
Vorab online veröffentlicht am 16.06.2020
Nachgewiesen in Scopus
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