Theo Rasing

Title

Optical Manipulation of Magnetic Order: Challenges and Opportunities

Abstract

The interaction of sub-picosecond laser pulses with magnetically ordered materials has developed into an exciting research topic in modern magnetism and spintronics. From the discovery of sub-picosecond demagnetization over a decade ago to the recent demonstration of magnetization reversal by a single 40 femtosecond laser pulse, the manipulation, of spins by ultra short laser pulses has become a fundamentally challenging topic with a potentially high impact for future spintronics, data storage and manipulation and quantum computation. In addition, when the time-scale of the perturbation approaches the characteristic time of the exchange interaction (~10-100 fs), the magnetic dynamics may enter a novel coupling regime where the exchange interaction may become time dependent. Using ultrashort excitations, we might be able to manipulate the exchange interaction itself. Such studies will require the excitation and probing of the spin and angular momentum contributions to the magnetic order at timescales of 10 fs and below, a challenge that might be met by the future fs X-ray FEL’s.