Satyendra Nath Gupta

Electron-hole asymmetry in the electron-phonon coupling in top-gated phosphorene transistor

Using in-situ Raman scattering from phosphorene channel in an electrochemically top-gated field effect transistor, we show that its phonons with A

Raman anomalies as signatures of pressure induced electronic topological and structural transitions in black phosphorus: Experiments and theory

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Probing 2D black phosphorus by quantum capacitance measurements.

symmetry depend much more strongly on concentration of electrons than that of holes, while the phonons with B

Spin liquid like Raman signatures in the hyperkagome iridate Na4Ir3O8

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Raman signatures of strong Kitaev exchange correlations in (Na1−xLix)2IrO3: Experiments and theory

symmetry are insensitive to doping. With first-principles theoretical analysis, we show that the observed electon-hole asymmetry arises from the radically different constitution of its conduction and valence bands involving

A new low temperature solid modification in 1-isothiocyanato-4-( trans ‑4-propylcyclohexyl)benzene (3CHBT) probed by Raman spectroscopy and quantum chemical calculations

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Pressure-induced Lifshitz transition in NbP: Raman, x-ray diffraction, electrical transport, and density functional theory

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Pressure-induced electronic and structural phase transitions in Dirac semimetal Cd3As2: Raman study

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Metallic monoclinic phase in VO2 induced by electrochemical gating: In situ Raman study

bonding states respectively, whose symmetry permits coupling with only the phonons that preserve the lattice symmetry. Thus, Raman spectroscopy is a non-invasive tool for measuring electron concentration in phosphorene-based nanoelectronic devices.

Effect of resonance scattering on Josephson current through a superconductor-normal-metal-superconductor junction

We report high-pressure Raman experiments of black phosphorus up to 24 GPa. The linewidths of first-order Raman modes A(g)(1), B-2g, and A(g)(2) of the orthorhombic phase show a minimum at 1.1 GPa. Our first-principles density functional analysis reveals that this is associated with the anomalies in electron-phonon coupling at the semiconductor to topological insulator transition through inversion of valence and conduction bands marking a change from trivial to nontrivial electronic topology. The frequencies of B-2g and A(g)(2) modes become anomalous in the rhombohedral phase at 7.4 GPa, and new modes appearing in the rhombohedral phase show anomalous softening with pressure. This is shown to originate from unusual structural evolution of black phosphorous with pressure, based on first-principles theoretical analysis.