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Femtosecond (fs)-resolved simultaneous measurements of charge and spin dynamics reveal the coexistence of two different quasi-particle excitations in colossal magneto-resistive (CMR) manganites, with {em fs} and {em ps} relaxation times respectively. Their populations reverse size above a {em photoexcitation-intensity-threshold} coinciding with a sudden antiferro-to-ferromagnetic switching during $<$100 fs laser pulses. We present evidence that fast, metallic, mobile quasi--electrons dressed by {em quantum spin fluctuations} coexist with slow, localized, polaronic charge carriers in non-equilibrium phases. This may be central to CMR transition and leads to a laser-driven charge reorganization simultaneously with quantum fs magnetism via an emergent quantum-spin/charge/lattice transient coupling.
We study theoretically the magnetic and electric properties of the interface between two antiferromagnetic and insulating manganites: La0.5Ca0.5MnO3, a strong correlated insulator, and CaMnO3, a band-insulator. We find that a ferromagnetic and metall
The dynamics of the photoinduced commensurate to incommensurate charge density wave (CDW) phase transition in 4Hb-TaSe2 are investigated by femtosecond electron diffraction. In the perturbative regime the CDW reforms on a 150 ps timescale, which is t
We employ time-resolved resonant x-ray diffraction to study the melting of charge order and the associated insulator-metal transition in the doped manganite Pr$_{0.5}$Ca$_{0.5}$MnO$_3$ after resonant excitation of a high-frequency infrared-active lat
We study the mechanism of orbital-order melting observed at temperature T_OO in the series of rare-earth manganites. We find that many-body super-exchange yields a transition-temperature T_KK that decreases with decreasing rare-earth radius, and incr
We study the structural, magnetic, transport and electronic properties of LaCoO$_3$ with Sr/Nb co-substitution, i.e., La$_{(1-2x)}$Sr$_{2x}$Co$_{(1-x)}$Nb$_{x}$O$_3$ using x-ray and neutron diffraction, dc and ac-magnetization, neutron depolarization