相关论文: Generation of Phonons with Angular Momentum During…
Despite the growing interest in phonon angular momentum (AM) in recent years, current studies remain limited to a few materials due to the constraints imposed by time reversal symmetry on macroscopic phonon AM. In this work, we…
Quantum theory of spin relaxation in the elastic environment is revised with account of the concept of a phonon spin recently introduced by Zhang and Niu (PRL 2014). Similar to the case of the electromagnetic field, the division of the…
The ultrafast non-thermal control of magnetization has recently become feasible in canted antiferromagnets through photomagnetic instantaneous pulses [A.V. Kimel {\it et al.}, Nature {\bf 435}, 655 (2005)]. In this experiment circularly…
We study of the ultrafast dynamics of the atomic angular momentum in ferrimagnets irradiated by laser pulses. My apply a quantum atomistic spin approach based on the Monte Carlo technique. Our model describes the coherent transfer of…
Electronic excitations in a ferromagnet can trigger ultrafast spin dynamics with potential applications in a speed increase in magnetic recording. The project investigates ultrafast magnetization dynamics, which is driven in metallic layers…
Time-domain femtosecond laser spectroscopic measurements of the ultrafast lattice dynamics in 2H-MoTe2 bulk crystals were carried out to understand the carrier-phonon interactions that govern electronic transport properties. An unusually…
The surprising discovery of ultrafast demagnetization -- where electric field of femtosecond laser pulse couples to electrons of a ferromagnetic (FM) layer causing its magnetization vector {\em to shrink while not rotating}, is also assumed…
The interaction between free electrons and laser-induced near-fields provides a platform to study ultrafast processes and quantum phenomena while enabling precise manipulation of electron wavefunctions through linear and orbital momentum…
Nonlinear frequency conversion by optical rectification, as well as difference- and sum-frequency generation are fundamental processes for producing electromagnetic radiation at different frequencies. Here, we demonstrate that coherently…
During nuclear fission, a heavy nucleus splits into two rotating fragments. The associated angular momentum is large, yet the mechanism of its generation and its dependence on the mass of fragments remain poorly understood. In this Letter,…
High-order harmonic generation (HHG) in solids is profoundly influenced by the dephasing of the coherent electron-hole motion driven by an external laser field. The exact physical mechanisms underlying this dephasing, crucial for accurately…
A theory of magnetophonon resonance in quantum wells in a magnetic field tilted to the perpendicular to 2DEG is developed. The resonance is due to the resonant interaction of 2D conduction electrons with the longitudinal optic phonons. The…
A dependence of a relaxation rate on the shape of the demagnetized region for a longitudinal evolution of total magnetization to its equilibrium value following the ultrafast demagnetization is demonstrated. This shape-dependence is caused…
We demonstrate optical control of magnons using femtosecond laser pulses by performing ab-initio real-time time-dependent density functional theory (TDDFT) simulations. We predict that the spin-wave dynamics in Fe$_{50}$Ni$_{50}$ can be…
The orbital angular momenta (OAM) of electrons play an increasingly important role in ultrafast electron and magnetization dynamics. In this theoretical study, we investigate the electron dynamics induced by femtosecond laser pulses in a…
In this letter, we provide a microscopic model for the ultrafast remagnetization of atomic moments already quenched above Stoner-Curie temperature by a strong laser fluence. Combining first principles density functional theory, atomistic…
We ask the question of how angular momentum is conserved in electroweak interaction processes. To introduce the problem with a minimum of mathematics, we first raise the same issue in elastic scattering of a circularly polarized photon by…
Experimentally observed ultrafast all-optical magnetization reversal in ferrimagnetic metals and heterostructures based on antiferromagnetically coupled ferromagnetic $d-$ and $f-$metallic layers relies on intricate energy and angular…
The generation of angular momentum in fissioning nuclei is not well understood. The predictions of different models disagree, particularly concerning the correlation between the fragments' angular momenta. In this article, a time-dependent…
The femtosecond optical pump-probe technique was used to study dynamics of photoexcited electrons and coherent optical phonons in transition metals Zn and Cd as a function of temperature and excitation level. The optical response in time…