Related papers: Ultrafast Magnetization Dynamics in Diluted Magnet…
We derive a master equation that allows us to study non-equilibrium dynamics of a quantum antiferromagnet. By resorting to spin-wave theory, we obtain a closed analytic form for the magnon decay rates. These turn out to be closely related…
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…
Time-resolved magneto-optical Kerr spectroscopy of ferromagnetic InMnAs reveals two distinct {\em demagnetization} processes -- fast ($<1$ ps) and slow ($\sim$100 ps). Both components diminish with increasing temperature and are absent…
The interplay of disorder and spin-fluctuation effects in a disordered antiferromagnet is studied. In the weak-disorder regime (W \le U), while the energy gap decreases rapidly with disorder, the sublattice magnetization, including quantum…
Recent experimental results have pushed the limits of magnetization dynamics to pico- and femtosecond timescales. This ultra-fast spin dynamics occurs in extreme conditions of strong and rapidly varying fields and high temperatures. This…
Electron spin relaxation induced by phonon-mediated s-d exchange interaction in a II-VI diluted magnetic semiconductor quantum dot is investigated theoretically. The electron-acoustic phonon interaction due to piezoelectric coupling and…
Ultrafast magnetization dynamics induced by femtosecond laser pulses have been measured in ferrimagnetic Co0.8Gd0.2, Co.74Tb.26 and Co.86Tb.14 alloys. Using element sensitivity of X-ray magnetic circular dichroism at the Co L3, Tb M5 and Gd…
We present magnetization studies in a series of phase separated La$_{0.5}$Ca$%_{0.5}$MnO$_{3}$ samples, with different low temperature fractions of the ferromagnetic (FM) and charge ordered-antiferromagnetic (CO-AFM) phases. A particular…
Laser induced ultrafast demagnetization is the process whereby the magnetic moment of a ferromagnetic material is seen to drop significantly on a timescale of $10-100$s of femtoseconds due to the application of a strong laser pulse. If this…
We predict that a novel bias-voltage assisted magnetization reversal process will occur in Mn doped II-VI semiconductor quantum wells or heterojunctions with carrier induced ferromagnetism. The effect is due to strong exchange-coupling…
Inertial magnetization dynamics have been predicted at ultrahigh speeds, or frequencies approaching the energy relaxation scale of electrons, in ferromagnetic metals. Here we identify inertial terms to magnetization dynamics in thin…
The magnetic phase diagram of CuFeO2 as a function of applied magnetic field and temperature is thoroughly explored and expanded, both for magnetic fields applied parallel and perpendicular to the material's c-axis. Pulsed field…
The stabilization of long-range magnetic order in nominally non-magnetic semi-conductors using femtosecond light pulses is an exciting yet experimentally challenging goal. Theoretical studies indicate that certain non-magnetic…
In (2+1)-dimensional QED with a Chern-Simons term, we show that spontaneous magnetization occurs in the context of finite density vacua, which are the lowest Landau levels fully or half occupied by fermions. Charge condensation is shown to…
Atomistic spin model simulations are immensely useful in determining temperature dependent magnetic prop- erties, but are known to give the incorrect dependence of the magnetization on temperature compared to exper- iment owing to their…
We analyze laser-induced ultrafast, spatially inhomogeneous magnetization dynamics of epitaxial Co/Cu(001) films in a 0.4-10 nm thickness range with time-resolved magnetization-induced second harmonic generation, which probes femtosecond…
We develop a finite temperature mean field theory in the path integral picture for an extremely dilute system of interacting Fermions in a plane. In the limit of short ranged interactions, the system is shown to undergo a phase transition…
We present a practical algorithm for partially relaxing multiwell energy densities such as pertain to materials undergoing martensitic phase transitions. The algorithm is based on sequential lamination, but the evolution of the…
We report experimental evidence of the effect of an applied magnetic field on the non-thermal magnetic relaxation in a disk-shaped type-I lead superconductor. The time evolution of the irreversible magnetization proves to be logarithmic for…
The mechanism underlying femtosecond laser pulse induced ultrafast magnetization dynamics remains elusive despite two decades of intense research on this phenomenon. Most experiments focused so far on characterizing magnetization and charge…