Selected Works
Effect of Rashba spin-orbit coupling and next-nearest-neighbor hopping on superconductivity in the square-octagon lattice
R. Kiran and A. Taraphder
Physical Review B, 113, 104512 (2026)
[Article]
This work studies superconductivity in the square-octagon lattice, where flat bands and Van Hove singularities enhance the density of states. Using the Bogoliubov-de Gennes formalism, we examine how next-nearest-neighbor hopping and Rashba spin-orbit coupling reshape superconducting domes, superfluid stiffness, and induced triplet correlations.
Possible realization of hyperbolic plasmons in a few-layered rhenium disulfide
R. Kiran, Dimitar Pashov, Mark van Schilfgaarde, Mikhail I. Katsnelson, A. Taraphder, and Swagata Acharya
Condensed Matter, 10, 40 (2025)
[Article] · [arXiv]
This study explores anisotropic optical behavior in few-layer rhenium disulfide. The in-plane structural anisotropy allows metallic and dielectric responses along different directions, giving rise to hyperbolic plasmon modes in the ultraviolet frequency range. The tunability of this regime depends on the number of layers, making ReS₂ a promising platform for hyperbolic photonics.
Effect of correlated disorder on superconductivity in a kagome lattice: A Bogoliubov-de Gennes analysis
R. Kiran, Sudipta Biswas, and Monodeep Chakraborty
Physical Review B, 110, 184506 (2024)
[Article] · [ResearchGate]
This paper investigates an s-wave superconductor on a kagome lattice in the presence of correlated disorder. Using the Bogoliubov-de Gennes formalism, we study how disorder correlations modify the superconducting order parameter and superfluid stiffness. The results show a bimodal distribution of the pairing amplitude at strong correlation strengths, emphasizing the role of lattice geometry in disordered superconductors.
Population migration and COVID-19
R. Kiran, Madhumita Roy, Syed Abbas, and A. Taraphder
Nonautonomous Dynamics and Systems, 8, 251–266 (2021)
[Article] · [arXiv]
This work models population migration and its impact on infectious disease spread during and after punctuated lockdowns. The model describes multi-city migration, computes the basic reproduction number, and examines how migration rates influence outbreak dynamics. Repeated lockdown cycles produce damped oscillatory infection patterns, offering insight into lockdown timing and intensity.
Immunomodulatory role of black tea in the mitigation of cancer induced by inorganic arsenic
R. Kiran, Swati Tyagi, Syed Abbas, Madhumita Roy, and A. Taraphder
European Physical Journal Plus, 135, 735 (2020)
[Article] · [arXiv]
This work develops a mathematical model for tumor and normal cell dynamics under the influence of inorganic arsenic and an immunomodulator, black tea. The model shows that variable immune-cell influx can reduce tumor populations while maintaining healthy cell levels. Stability analysis and numerical simulations indicate how immune modulation may help mitigate cancer growth.