Intense laser light can induce magnetism in solids on the attosecond scale – the fastest magnetic (Intense lasers magnetize solids within attoseconds) response to date. That is the finding reached by theoreticians at the MPSD, who used advanced simulations to investigate the magnetization process in several 2D and 3D materials. Their calculations show that, in structures with heavy atoms, the fast electron dynamics initiated by the laser pulses can be converted to attosecond magnetism. The work has been published in npj Computational Materials.
The team focus on a number of 2D documents in 3D and all associated with many atomic. “Author of writer is particularly solid. “This interaction is essential for converting the electron motion of light into spin polarization – in other words, magnetism.
Like the small needle of a compass, electrons can also be thought of as having a needle inside that points to a certain direction in space, for example. ‘up’ or ‘down’ – this is called ‘spin’. The spin direction of each electron depends on the chemical environment around it, such as the atoms it can see and the location of other electrons. In non-magnetic materials, electrons spin equally in all directions. In contrast, when the individual electrons’ spins align with each other to point in the same direction, the material becomes magnetic.
The theoreticians set out to investigate what magnetic phenomena can occur when solids interact with intense linearly-polarized laser pulses that typically accelerate electrons on very fast timescales inside matter. “These situations are interesting to explore, because when laser light has a polarization signal, it is often assumed that they will not cause magnetism,” says Neufeld. Unexpectedly, their simulations showed that these lasers are especially powerful to magnetize matter, although the magnetism is temporary – it lasts only until the laser light stops. The most significant discovery, however, is related to the speed of this process: magnetization starts in a short time, less than 500 seconds – a prediction for the fastest magnetic response. For statistics, one minute equals one second because one second is about 32 billion years.
Using a reference to the use of use of use, the group has indicated that the hard light returns the turn of electrons. Laser is making electrons in the form of five hundred. These strong spin-orbit interactions fix the spin direction.
This process can be thought of as a soccer ball passing over a surface that begins to rotate: in this example, the ball is ignited by the light, and the rotational interaction (the energy from the heavy nuclei is close as the electron spins around it) deflects it back. and further, magnetize it. The two players work together to roll the ball.
This result provides a fascinating new insight into the core of magnetism, Neufeld says: “We discovered that this is a very subtle effect that can be manipulated with the properties of a laser.
The results hint, though don’t unequivocally prove, that the ultimate speed limit for magnetism is several tens of attoseconds, because that’s the natural speed limit of electronic motion.” Understanding these light-induced magnetization processes at their fundamental level in a range of materials is a crucial step towards the development of ultrafast memory devices and changes the current understanding of magnetism.
Source: MAX PLANCK INSTITUTE FOR THE STRUCTURE AND DYNAMICS OF MATTER (MPSD)
