Phys.org September 19, 2024
Bulk van der Waals (vdW) superlattices 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. An international team of researchers in the (USA- MIT, National High Magnetic Field Laboratory, Harvard, Japan) reported 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 was made anisotropic by the modulation and exhibited commensurability oscillations paralleling lithographically modulated 2D systems. They found 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 suggests superconductivity in SrTa2S5 was spatially modulated and mismatched between adjacent TMD layers. According to the researchers the SrTa2S5 may present a pathway for microscopic evaluation of this unconventional order and SrTa2S5 establishes bulk vdW superlattices as versatile platforms to address long-standing predictions surrounding modulated electronic phases in the form of nanoscale vdW devices to macroscopic crystals… read more. TECHNICAL ARTICLE
Periodically modulated crystals and a structurally modulated bulk superlattice. Credit: Nature volume 631, pages 526–530, 30 July 2024