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Devarakonda A, Chen A, Fang S, Graf D, Kriener M, Akey AJ, Bell DC, Suzuki T, Checkelsky JG. Evidence of striped electronic phases in a structurally modulated superlattice. Nature 2024; 631:526-530. [PMID: 38961299 DOI: 10.1038/s41586-024-07589-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2023] [Accepted: 05/21/2024] [Indexed: 07/05/2024]
Abstract
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) moiré 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.
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Affiliation(s)
- A Devarakonda
- Department of Physics, Massachusetts Institute of Technology, Cambridge, MA, USA
- Department of Applied Physics and Applied Mathematics, Columbia University, New York, NY, USA
| | - A Chen
- Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - S Fang
- Department of Physics, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - D Graf
- National High Magnetic Field Laboratory, Tallahassee, FL, USA
| | - M Kriener
- RIKEN Center for Emergent Matter Science (CEMS), Wako, Japan
| | - A J Akey
- Center for Nanoscale Systems, Harvard University, Cambridge, MA, USA
| | - D C Bell
- Center for Nanoscale Systems, Harvard University, Cambridge, MA, USA
- John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, MA, USA
| | - T Suzuki
- Department of Physics, Toho University, Funabashi, Japan
| | - J G Checkelsky
- Department of Physics, Massachusetts Institute of Technology, Cambridge, MA, USA.
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Devarakonda A, Inoue H, Fang S, Ozsoy-Keskinbora C, Suzuki T, Kriener M, Fu L, Kaxiras E, Bell DC, Checkelsky JG. Clean 2D superconductivity in a bulk van der Waals superlattice. Science 2020; 370:231-236. [DOI: 10.1126/science.aaz6643] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2019] [Accepted: 08/21/2020] [Indexed: 11/02/2022]
Abstract
Advances in low-dimensional superconductivity are often realized through improvements in material quality. Apart from a small group of organic materials, there is a near absence of clean-limit two-dimensional (2D) superconductors, which presents an impediment to the pursuit of numerous long-standing predictions for exotic superconductivity with fragile pairing symmetries. We developed a bulk superlattice consisting of the transition metal dichalcogenide (TMD) superconductor 2H-niobium disulfide (2H-NbS2) and a commensurate block layer that yields enhanced two-dimensionality, high electronic quality, and clean-limit inorganic 2D superconductivity. The structure of this material may naturally be extended to generate a distinct family of 2D superconductors, topological insulators, and excitonic systems based on TMDs with improved material properties.
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Affiliation(s)
- A. Devarakonda
- Department of Physics, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - H. Inoue
- Department of Physics, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - S. Fang
- Department of Physics, Harvard University, Cambridge, MA 02138, USA
| | - C. Ozsoy-Keskinbora
- John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, MA 02138, USA
| | - T. Suzuki
- Department of Physics, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - M. Kriener
- RIKEN Center for Emergent Matter Science (CEMS), Wako 351-0198, Japan
| | - L. Fu
- Department of Physics, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - E. Kaxiras
- Department of Physics, Harvard University, Cambridge, MA 02138, USA
- John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, MA 02138, USA
| | - D. C. Bell
- John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, MA 02138, USA
- Center for Nanoscale Systems, Harvard University, Cambridge, MA 02138, USA
| | - J. G. Checkelsky
- Department of Physics, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
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Smeller MM, Heideman CL, Lin Q, Beekman M, Anderson MD, Zschack P, Anderson IM, Johnson DC. Structure of Turbostratically Disordered Misfit Layer Compounds [(PbSe)0.99]1[WSe2]1, [(PbSe)1.00]1[MoSe2]1, and [(SnSe)1.03]1[MoSe2]1. Z Anorg Allg Chem 2012. [DOI: 10.1002/zaac.201200408] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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