Speaker
Description
Recently, ultrafast electron dynamics have been successfully controlled, and measured, with intense femtosecond lasers. This has enabled attosecond probing of many fundamental physical phenomena and material properties and should advance petahertz scale electronic devices with Lightwave coherent manipulation. At the same time, the field of ultrafast magnetism has rapidly evolved, enabling analogous types of coherent control directives, but for electronic spins. Such control can be employed for spin transfer protocols, optical magnetic switches, Lightwave magnetic phase manipulation, and spin currents for spintronics. In principle, this allows merging strong-field-induced electron dynamics with spin dynamics, enabling Petahertz spintronics. I will briefly introduce the prospects and motivation for the field. Subsequently, I will review our recent advancements in these directions. First, I will present ab-initio predictions for CEP-controlled transient magnetic phases driven by intense few-cycle lasers in initially non-magnetic materials. I will next show that by using few-cycle lasers with inherently broken time-reversal symmetry, magnetization can be generated even with linearly-polarized pulses. By introducing two-color tailored laser driving, the out-of-plane magnetization generated in 2D materials can be coherently rotated into 3D spin dynamics control, enabling a wider array of available magnetic phases. This effect arises by precise symmetry breaking in tailored two-color fields that manipulates mirror symmetries, time-reversal symmetry, and inversion symmetry, all of which play a critical role in photocurrent generation and spin dynamics (which I will show are intimately related phenomena). Lastly, I’ll introduce measures for evaluating the degree of these symmetry breakings in a tailored laser field, which can also be employed for ultrafast magnetic phase detection.