Laser-Induced Skyrmion Writing and Erasing in an Ultrafast Cryo-Lorentz Transmission Electron Microscope

Abstract

We demonstrate that light-induced heat pulses of different duration and energy can write Skyrmions in a broad range of temperatures and magnetic field in FeGe. Using a combination of camera-rate and pump-probe cryo-Lorentz transmission electron microscopy, we directly resolve the spatiotemporal evolution of the magnetization ensuing optical excitation. The Skyrmion lattice was found to maintain its structural properties during the laser-induced demagnetization, and its recovery to the initial state happened in the sub-μs to μs range, depending on the cooling rate of the system.

Generation and Characterization of Attosecond Microbunched Electron Pulse Trains via Dielectric Laser Acceleration

“…Ultrashort electron pulses find various applications in research and technology, including ultrafast diffraction [1][2][3], ultrafast electron microscopy [4][5][6][7], as well as ultrafast photon generation [8]. Many of these techniques operate with electron pulse durations in the realm of femtoseconds.…”

“…The temporal resolution of lasertriggered electron sources is usually limited by the temporal duration of the electron-releasing laser pulses and subsequent dispersive broadening of the electron pulses. Typical electron pulse durations at the sample are in the range of 30 fs to 1 ps [1][2][3][4][5][6][7][8][9]. Schemes have been proposed and demonstrated to compress the electron pulses at the sample, see for example [10,11].…”

Weak Crystallization of Fluctuating Skyrmion Textures in MnSi

“…In contrast, changes of the topological properties require that the magnetization is capable of vanishing on short length and time scales. The associated microscopic mechanisms underlying the transition of skyrmions into different types of conventional long-range magnetic order have been explored in a large number of theoretical and experimental studies [2][3][4][5][6][7][8].A major unresolved question concerns, in contrast, the formation of skyrmion lattice order when starting from a state that is essentially paramagnetic and dominated by an abundance of fluctuations such that the local magnetization, on a coarse-grained level, practically vanishes on average [9][10][11][12][13][14][15]. This alludes to the question whether topologically non-trivial characteristics exist already in * a paramagnetic state, and how they may be accounted for in the framework of the present-day classification of phase transitions [16][17][18].…”

Optically Driven Collective Spin Excitations and Magnetization Dynamics in the Néel-type Skyrmion Host GaV4S8

“…Interest has also extended to magnetic topological defects known as skyrmions (Sks) [11], fueled by their importance in memory technology [12][13][14], spintronics [15], and emergent electromagnetism [16][17][18]. Recently, optical stimulus has been successfully used to write and erase individual Sks [19], confirm their topological robustness [20], and identify new metastable Sk states [21].…”