Presentation Information
[1P28]RF Injection scanning tunneling spectroscopy of a superconducting NbSe2 Surface
*Md Arafat Ali1, Zhipeng Wang1,3, Mohammad Ikram Hossain1,3, Ferdous Ara2, Syed Mohammad Fakruddin Shahed2, Tadahiro KOMEDA2,3 (1. Department of Chemistry, Graduate School of Science, Tohoku University., 2. Institute of Multidisciplinary Research for Advanced Materials (IMRAM), Tohoku University. , 3. Center for Spintronics Research Network, Tohoku University)
We investigated the influence of RF injection on the STS in coexisting 2H and 1T phases of superconducting NbSe2 through combined experiments and simulations. We found that the superconducting gap decreases when moving the tip from the 2H domain into the 1T domain under zero RF conditions. Under RF excitation, quasiparticles exhibited symmetric splitting that varied linearly with the RF electric field (VAC), and the spectra showed smooth profiles with two enhanced peaks near +/- eVAC instead of discrete replica peaks separated by the photon energy. The behavior was well reproduced by a simulation using the photon-assisted tunneling (PAT) model. Interestingly, the slope of the linear energy shift differed between the two phases, with the 1T phase exhibiting a smaller coefficient, attributed to its distinct dielectric constant compared to the 2H phase. These findings highlight the sensitivity of RF-STM techniques to local dielectric properties and offer a pathway toward localized chemical analysis in quantum materials.