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Article
Open AccessSelective interlayer ferromagnetic coupling between the Cu spins in YBa2Cu3O7−x grown on top of La0.7Ca0.3MnO3
Studies to date on ferromagnet/d-wave superconductor heterostructures focus mainly on the effects at or near the interfaces while the response of bulk properties to heterostructuring is overlooked. Here we use re...
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Article
Open AccessGlass-like recovery of antiferromagnetic spin ordering in a photo-excited manganite Pr0.7Ca0.3MnO3
Electronic orderings of charges, orbitals and spins are observed in many strongly correlated electron materials and revealing their dynamics is a critical step toward undertsanding the underlying physics of im...
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Article
Open AccessUltrafast charge localization in a stripe-phase nickelate
Self-organized electronically ordered phases are a recurring feature in correlated materials, resulting in, for example, fluctuating charge stripes whose role in high-TC superconductivity is under debate. However...
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Article
Phase fluctuations and the absence of topological defects in a photo-excited charge-ordered nickelate
The dynamics of an order parameter's amplitude and phase determines the collective behaviour of novel states emerging in complex materials. Time- and momentum-resolved pump-probe spectroscopy, by virtue of mea...
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Chapter and Conference Paper
Ultrafast Gigantic Photo-Response in Charge-Ordered Organic Salt (EDO-TTF)2PF6 on 10-fs time scales
The initial dynamics of photo-induced phase transition in charge-ordered organic salt (EDO-TTF)2PF6 was investigated using 10-fs near-infrared laser pulses. We observed sub-20-fs gigantic photo-responses (|∆R/R|>...
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Chapter and Conference Paper
Time-resolved X-ray Absorption Spectroscopy of Photoinduced Insulator-Metal Transition in a Colossal Magnetoresistive Manganite
We studied the ultrafast insulator-metal transition in a manganite by means of picosecond X-ray absorption at the O K- and Mn L-edges, probing photoinduced changes in O-2p and Mn-3d electronic states near the Fer...
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Chapter and Conference Paper
Coherent Orbital Waves in Manganites
High temporal resolution pump-probe experiments are used to excite and observe highfrequency orbital oscillations in the room temperature phase of 2D and 3D Colossal Magneto-Resistive manganites.
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Article
Coherent orbital waves in the photo-induced insulator–metal dynamics of a magnetoresistive manganite
Photo-excitation can drive strongly correlated electron insulators into competing conducting phases1,2, resulting in giant and ultrafast changes of their electronic and magnetic properties. The underlying non-equ...
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Chapter and Conference Paper
Lattice Motions from THz phonon polaritons measured with Femtosecond X-ray Diffraction
We use femtosecond x-ray diffraction to measure the coherent lattice displacements associated with the excitation and propagation of THz phonon polaritons in LiTaO3.
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Article
Tracking the motion of charges in a terahertz light field by femtosecond X-ray diffraction
The elementary particles of light that propagate through air are photons. But when light propagates through condensed matter, it couples to the underlying lattice, resulting in complex particles such as polari...
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Chapter and Conference Paper
Phase Transition in strongly-correlated VO2: Time-domain Assignment of Cause and Effect
We establish time-domain hierarchy between structural and electronic effects in the strongly correlated system VO2. The insulator-to-metal transition is driven directly by structural change rather than by electro...
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Chapter and Conference Paper
Femtosecond Near Edge X-ray Absorption Measurement of the VO2 Phase Transition.
We measure the insulator-to-metal transition in VO2 using femtosecond Near-Edge X-ray Absorption. Sliced pulses of synchrotron radiation are used to detect the photo-induced dynamics at the 516-eV Vanadium L3 edg...
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Chapter and Conference Paper
Femtosecond X-ray Pulses from a Synchrotron
An important frontier in ultrafast science is the application of femtosecond x-ray pulses to the study of structural dynamics in condensed matter. We show that femtosecond laser pulses can be used to generate ...
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Article
Generation of femtosecond X-ray pulses via laser–electron beam interaction
The generation of femtosecond X-ray pulses will have important scientific applications by enabling the direct measurement of atomic motion and structural dynamics in condensed matter on the fundamental time sc...
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Chapter and Conference Paper
Generation of “Dark” Femtosecond Synchrotron Pulses from the Advanced Light Source
Femtosecond optical pulses extract ~100 fs slices of electrons from the electron beam at the ALS. We directly measure the resulting ~500-fs “dark” pulses in the synchrotron radiation from a bend-magnet.
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Chapter and Conference Paper
Temporal Broadening Of Femtosecond High Harmonic Radiation
Measurement of femtosecond high harmonic radiation indicates that significant pulse shortening can be accomplished by limiting the transverse intensity variation of the generating laser pulse.
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Chapter and Conference Paper
Ultrafast Structural Dynamics in InSb Probed by Time-Resolved X-ray Diffraction
Ultrafast structural dynamics in InSb are studied using time-resolved x-ray diffraction. A delayed onset of significant lattice expansion and an indication of subpicosecond disordering are observed.
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Chapter and Conference Paper
Ultrafast Dephasing Dynamics and Multi-Level Electronic Structure of InP Nanocrystals
Femtosecond three-pulse photon echoes and nanosecond hole-burning are used to study dephasing dynamics and electronic level structure in InP nanocrystals. The temperature dependence of the echo decay rate show...
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Chapter and Conference Paper
Femtosecond X-Rays Generated via 90° Thomson Scattering
We have developed a unique source of femtosecond x-rays operating in the 300 fs, 0.4 Å regime[l], which will allow us to apply x-ray techniques with ultrafast time resolution to directly probe the structural d...
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Chapter and Conference Paper
Measurement of High Harmonic Pulse Durations Via Laser Assisted X-Ray Photoionization
Ultrashort x-ray pulses are powerful diagnostic tools, combining the temporal resolution typically reserved for optical (laser) pulses with atomic scale spatial resolution which, in principle, can be achieved ...
