The coupling of phonons with collective modes and single-particle gap excitations associated with one-(1d) and two-directional (2d) electronically driven charge-density wave (CDW) ordering in metallic RTe3 are investigated as a function of rare-earth ion chemical pressure (R = Tb;Dy;Ho) using femtosecond pump-probe spectroscopy. From the T dependence of the CDW gap and the amplitude mode, we find that while the transition to a 1d-CDW ordered state at Tc1 initially proceeds in an exemplary mean- field-like fashion, below Tc1, gap is depressed and departs from the mean-?eld behavior.
COBISS.SI-ID: 22302759
We use ultrashort intense laser pulses to study superconducting state vaporization dynamics in La2-xSrxCuO4 on the femtosecond time scale. The energy density required to vaporize the superconducting state is significantly greater than the condensation energy density, indicating that the quasiparticles share a large amount of energy with the boson glue bath. Considering in detail both spin and lattice energy relaxation pathways which take place on the relevant time scale of ~10 ps, the experiments appear to favor phonon-mediated pair-breaking mechanisms over spin-mediated pair breaking.
COBISS.SI-ID: 22209063