{"database":"biostudies-literature","file_versions":[],"scores":null,"additional":{"submitter":["Karnatak P"],"funding":["Core Research for Evolutional Science and Technology","Swiss National Science Foundation","European Research Council","Swiss Nanoscience Institute, University of Basel","Japan Society for the Promotion of Science"],"pagination":["2454-2459"],"full_dataset_link":["https://www.ebi.ac.uk/biostudies/studies/S-EPMC10103330"],"repository":["biostudies-literature"],"omics_type":["Unknown"],"volume":["23(7)"],"pubmed_abstract":["Superconductivity in van der Waals materials, such as NbSe<sub>2</sub> and TaS<sub>2</sub>, is fundamentally novel due to the effects of dimensionality, crystal symmetries, and strong spin-orbit coupling. In this work, we perform tunnel spectroscopy on NbSe<sub>2</sub> by utilizing MoS<sub>2</sub> or hexagonal boron nitride (hBN) as a tunnel barrier. We observe subgap excitations and probe their origin by studying various heterostructure designs. We show that the edge of NbSe<sub>2</sub> hosts many defect states, which strongly couple to the superconductor and form Andreev bound states. Furthermore, by isolating the NbSe<sub>2</sub> edge we show that the subgap states are ubiquitous in MoS<sub>2</sub> tunnel barriers but absent in hBN tunnel barriers, suggesting defects in MoS<sub>2</sub> as their origin. Their magnetic nature reveals a singlet- or a doublet-type ground state, and based on nearly vanishing <i>g</i> factors or avoided crossings of subgap excitations, we highlight the role of strong spin-orbit coupling."],"journal":["Nano letters"],"pubmed_title":["Origin of Subgap States in Normal-Insulator-Superconductor van der Waals Heterostructures."],"pmcid":["PMC10103330"],"funding_grant_id":["20H00354","JPMJCR15F3","787414","19H05790"],"pubmed_authors":["Karnatak P","Schonenberger C","Forro L","Watanabe K","Mingazheva Z","Berger H","Taniguchi T"],"additional_accession":[]},"is_claimable":false,"name":"Origin of Subgap States in Normal-Insulator-Superconductor van der Waals Heterostructures.","description":"Superconductivity in van der Waals materials, such as NbSe<sub>2</sub> and TaS<sub>2</sub>, is fundamentally novel due to the effects of dimensionality, crystal symmetries, and strong spin-orbit coupling. In this work, we perform tunnel spectroscopy on NbSe<sub>2</sub> by utilizing MoS<sub>2</sub> or hexagonal boron nitride (hBN) as a tunnel barrier. We observe subgap excitations and probe their origin by studying various heterostructure designs. We show that the edge of NbSe<sub>2</sub> hosts many defect states, which strongly couple to the superconductor and form Andreev bound states. Furthermore, by isolating the NbSe<sub>2</sub> edge we show that the subgap states are ubiquitous in MoS<sub>2</sub> tunnel barriers but absent in hBN tunnel barriers, suggesting defects in MoS<sub>2</sub> as their origin. Their magnetic nature reveals a singlet- or a doublet-type ground state, and based on nearly vanishing <i>g</i> factors or avoided crossings of subgap excitations, we highlight the role of strong spin-orbit coupling.","dates":{"release":"2023-01-01T00:00:00Z","publication":"2023 Apr","modification":"2025-04-04T12:44:09.893Z","creation":"2025-04-04T12:44:09.893Z"},"accession":"S-EPMC10103330","cross_references":{"pubmed":["36926934"],"doi":["10.1021/acs.nanolett.2c02777"]}}