Controlling High-Frequency Spin-Wave Dynamics Using Double-Pulse Laser Excitation

Superparamagnetic spin dynamics studied using selective excitation double Mössbauer spectroscopy.

A detailed study of spin dynamics in a 6 nm Fe3O4 ferrofluid using a substantially improved selective excitation double Mossbauer (SEDM) experimental technique has led to the unambiguous separation of static disorder, collective excitations, and moment reversals. Superparamagnetic spin flips have been observed through the appearance of an additional line in the SEDM spectrum, defining the energ...

Influence of Interface Thermal Resistance on Relaxation Dynamics of Metal-Dielectric Nanocomposite Materials under Ultrafast Pulse Laser Excitation

Nanocomposite materials, including noble metal nanoparticles embedded in a dielectric host medium, are interesting because of their optical properties linked to surface plasmon resonance phenomena. For studding of nonlinear optical properties and/or energy transfer process, these materials may be excited by ultrashort pulse laser with a temporal width varying from some femtoseconds to some hund...

Controlling rotational state distributions using two-pulse stimulated Raman excitation

Pulse compression and traveling wave excitation scheme

A single dispersive element is shown to be sufficient for simultaneous pulse compression and tilting of the pulse front, and therefore well-suited for traveling-wave excitation of targets. It is shown that in all the previous arrangements used for traveling wave excitation, spatially dependent group velocity dispersion occurs along the target. A compensated arrangement is proposed that provides...

High-intensity double-pulse X-ray free-electron laser

The X-ray free-electron laser has opened a new era for photon science, improving the X-ray brightness by ten orders of magnitude over previously available sources. Similar to an optical laser, the spectral and temporal structure of the radiation pulses can be tailored to the specific needs of many experiments by accurately manipulating the lasing medium, that is, the electron beam. Here we repo...