Optical Evidence for the Dynamic Jahn-Teller Effect in Nd0.7Sr0.3MnO3.

Giant Magneto-Resistance in Nd0.7Sr0.3MnO3 at Optical Frequencies

The optical properties of Nd0.7Sr0.3MnO3 thin films have been studied from 5 meV to 25 meV and from 0.25 eV to 3 eV, at temperatures from 15 K to 300 K and magnetic fields up to 8.9 T. A large transfer of spectral weight from high energy to low energy occurs as the temperature is decreased below 180 K, where the dc resistivity peaks, or as the magnetic field is increased. The optical data are f...

Optical conductivity of manganites: Crossover from Jahn-Teller small polaron to coherent transport in the ferromagnetic state

We report on the optical properties of the hole-doped manganites Nd0.7Sr0.3MnO3, La0.7Ca0.3MnO3, and La0.7Sr0.3MnO3. The low-energy optical conductivity in the paramagnetic-insulating state of these materials is characterized by a broad maximum near 1 eV. This feature shifts to lower energy and grows in optical oscillator strength as the temperature is lowered into the ferromagnetic state. It r...

The Influence of the Dynamic Jahn-Teller Effect on the Phonon-Scattering Mechanism at Acceptors in Semiconductors with Cubic Symmetry

The ground state of acceptors in cubic semiconductors is fourfold degenerate (I?,) and the interaction with the lattice vibrations leads to the possibility of a Jahn-Teller effect [l]. The extended nature of the wave function of these defects [ 2 ] has two important consequences : (i) the interaction is mainly with long-wavelength acoustic phonons, (ii) because of the large elastic energy assoc...

Evidence of dynamic Jahn-Teller distortions in two-dimensional crystalline molecular films

Observation of the dynamic Jahn-Teller effect in the excited states of nitrogen-vacancy centers in diamond.

The optical transition linewidth and emission polarization of single nitrogen-vacancy (NV) centers are measured from 5 K to room temperature. Interexcited state population relaxation is shown to broaden the zero-phonon line and both the relaxation and linewidth are found to follow a T(5) dependence for T < 100 K. This dependence indicates that the dynamic Jahn-Teller effect is the dominant deph...