nd - m at . s up r - co n ] 1 6 Se p 19 97 Electron - Phonon Interaction and Raman Linewidth in

v 2 [ co nd - m at . s up r - co n ] 1 6 Se p 20 02 Oxygen Phonon Branches in Detwinned YBa

ar X iv : c on d - m at / 0 20 91 97 v 1 [ co nd - m at . s up r - co n ] 9 S ep 2 00 2 Oxygen Phonon Branches

Phonon self-energy effects due to superconductivity in Bi2Sr2CaCu2O81d

Raman scattering of A1g phonons in Bi2Sr2CaCu2O81d single crystals ~d50.13, Tc586 K! has been measured as a function of temperature. We report an anomalous softening in the frequency and a decrease in the linewidth of the A1g phonon at 290 cm 21 ~O1,2 c-axis in-phase vibration! below Tc . We also confirm a smaller anomalous softening in the frequency of the A1g phonon at 465 cm 21 ~O3 c-axis vi...

Effects of resonant tunneling and dynamics of coherent interaction on intrinsic linewidth of quantum cascade lasers

A theoretical model for calculation of the intrinsic linewidth of QCLs is built on the basis of the quantum Langevin approach. It differs from the traditional rate equation model in that the resonant tunneling and the dynamics of coherent interaction can be considered. Results show that the coupling strength and the dephasing rate associated with resonant tunneling strongly affect the linewidth...

Raman Scattering in Charge Ordered Pr0.63Ca0.37MnO3 : Anomalous Temperature Dependence of Linewidth

– We report on the evolution of the Raman-active Ag phonon modes in the chargeordered manganite Pr0.63Ca0.37MnO3 as a function of temperature from 300K to 25K. Our studies reveal that the linewidths of the Ag(2) and Ag(4) phonons increase as temperature decreases. This anomalous temperature dependence of phonon lineshapes, seen for the first time in charge ordered manganites, can be quantitativ...