Evidence of striped electronic phases in a structurally modulated superlattice

• 成果类型: Article
• 署名作者: Devarakonda, A.; Chen, A.; Fang, S.; Graf, D.; Kriener, M.; Akey, A. J.; Bell, D. C.; Suzuki, T.; Checkelsky, J. G.
• 署名单位: Massachusetts Institute of Technology (MIT); Massachusetts Institute of Technology (MIT); State University System of Florida; Florida State University; RIKEN; Harvard University; Harvard University; Toho University; Columbia University
• 刊物名称: Nature
• ISSN/ISSBN: 0028-5679
• DOI: 10.1038/s41586-024-07589-5
• 发表日期: 2024-07-18
• 关键词: density wave state; total-energy calculations; magnetoresistance oscillations; TRANSITION; metal; ORDER; gas; superconductors; conductivity; field

摘要

The electronic properties of crystals can be manipulated by superimposing spatially periodic electric, magnetic or structural modulations. Long-wavelength modulations incommensurate with the atomic lattice are particularly interesting1, exemplified by recent advances in two-dimensional (2D) moir & eacute; materials2,3. Bulk van der Waals (vdW) superlattices4-8 hosting 2D interfaces between minimally disordered layers represent scalable bulk analogues of artificial vdW heterostructures and present a complementary venue to explore incommensurately modulated 2D states. Here we report the bulk vdW superlattice SrTa2S5 realizing an incommensurate one-dimensional (1D) structural modulation of 2D transition metal dichalcogenide (TMD) H-TaS2 layers. High-quality electronic transport in the H-TaS2 layers, evidenced by quantum oscillations, is made anisotropic by the modulation and exhibits commensurability oscillations paralleling lithographically modulated 2D systems9-11. We also find unconventional, clean-limit superconductivity in SrTa2S5 with a pronounced suppression of interlayer relative to intralayer coherence. The in-plane magnetic field dependence of interlayer critical current, together with electron diffraction from the structural modulation, suggests superconductivity12-14 in SrTa2S5 is spatially modulated and mismatched between adjacent TMD layers. With phenomenology suggestive of pair-density wave superconductivity15-17, SrTa2S5 may present a pathway for microscopic evaluation of this unconventional order18-21. More broadly, SrTa2S5 establishes bulk vdW superlattices as versatile platforms to address long-standing predictions surrounding modulated electronic phases in the form of nanoscale vdW devices12,13 to macroscopic crystals22,23. Evidence of modulated metallic and superconducting states stemming from an incommensurate structural stripe motif is reported in the bulk van der Waals superlattice SrTa2S5.