Solid State Physics Laboratory

About: Solid State Physics Laboratory is a facility organization based out in Delhi, India. It is known for research contribution in the topics: Quantum dot & Dielectric. The organization has 1754 authors who have published 2597 publications receiving 50601 citations.

Insulating state and giant nonlocal response in an InAs/GaSb quantum well in the quantum Hall regime.

Abstract: We present transport measurements performed in InAs=GaSb double quantum wells. At the electronhole crossover tuned by a gate voltage, a strong increase in the longitudinal resistivity is observed with increasing perpendicular magnetic field. Concomitantly with a local resistance exceeding the resistance quantum by an order of magnitude, we find a pronounced nonlocal resistance signal of almost similar magnitude. The coexistence of these two effects is reconciled in a model of counterpropagating and dissipative quantum Hall edge channels providing backscattering, shorted by a residual bulk conductivity.

Infrared spectroscopic study of phonons coupled to charge excitations in FeSi

Abstract: From an investigation of the optical conductivity of FeSi single crystals using Fourier-transform infrared spectroscopy in the frequency range from 30 to 20 000 cm-l we conclude that the transverse effective charge of the Fe and Si ions is approximately 4e. Of the five optical phonons that are allowed by symmetry we observe only four, three of which have a Fano line shape presumably resulting from an interaction of these modes with the electronic continuum. We show that the large oscillator strength of the phonons results from a relatively weak coupling (lambda approximate to 0.1) of the lattice degrees of freedom to an electronic resonance above the semiconductor gap, which is also responsible for the large electronic polarizability (epsilon(infinity)approximate to 200) of the medium.

1s2p resonant inelastic x-ray scattering in alpha-Fe2O3

Abstract: We report experimental and theoretical results on the Fe K edge x-ray absorption spectrum and $1s2p$ resonant inelastic x-ray scattering (RIXS) spectra in $\ensuremath{\alpha}\ensuremath{-}{\mathrm{Fe}}_{2}{\mathrm{O}}_{3}.$ The results are interpreted using an ${\mathrm{FeO}}_{6}^{9\ensuremath{-}}$ cluster model with intra-atomic multiplet coupling and interatomic covalency hybridization. The $1s2p$ RIXS is treated as a coherent second-order optical process. It is shown that the double-peak structure in the pre-edge region of Fe K absorption spectrum is due to the cubic crystal-field splitting, and that the intensity of the ${e}_{g} {(t}_{2g})$ component in the $1s2p$ resonant inelastic spectrum is enhanced by tuning the incident photon energy to the ${e}_{g} {(t}_{2g})$ component in the absorption spectrum.

Polaron Polaritons in the Integer and Fractional Quantum Hall Regimes.

Abstract: Elementary quasiparticles in a two-dimensional electron system can be described as exciton polarons since electron-exciton interactions ensures dressing of excitons by Fermi-sea electron-hole pair excitations. A relevant open question is the modification of this description when the electrons occupy flat bands and electron-electron interactions become prominent. Here, we perform cavity spectroscopy of a two-dimensional electron system in the strong coupling regime, where polariton resonances carry signatures of strongly correlated quantum Hall phases. By measuring the evolution of the polariton splitting under an external magnetic field, we demonstrate the modification of polaron dressing that we associate with filling factor dependent electron-exciton interactions.