Abstract
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 Z3, i.e., three-state Potts-model symmetry. Thermal expansion, specific heat and magnetization measurements of the doped topological insulators NbxBi2Se3 and CuxBi2Se3 reveal that this symmetry breaking occurs at Tnem ≃ 3.8K above Tc ≃ 3.25K, along with an onset of superconducting fluctuations. Thus, before Cooper pairs establish long-range coherence at Tc, they fluctuate in a way that breaks the rotational invariance at Tnem and induces a crystalline distortion.
Recommended Citation
C. w. Cho et al., "Z₃-Vestigial Nematic Order Due to Superconducting Fluctuations in the Doped Topological Insulators NbₓBi₂Se₃ and CuₓBi₂Se₃," Nature Communications, vol. 11, no. 1, Nature Research, Jun 2020.
The definitive version is available at https://doi.org/10.1038/s41467-020-16871-9
Department(s)
Physics
International Standard Serial Number (ISSN)
2041-1723
Document Type
Article - Journal
Document Version
Final Version
File Type
text
Language(s)
English
Rights
© 2020 The Authors, All rights reserved.
Creative Commons Licensing
This work is licensed under a Creative Commons Attribution 4.0 License.
Publication Date
16 Jun 2020
PubMed ID
32546839
Comments
This work was supported by grants from the Research Grants Council of the Hong Kong Special Administrative Region, China (GRF-16302018, SBI17SC14, IEG16SC03). Y.S.H. acknowledges the support from the NSF-DMR 1255607.