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"... In a new study in Nature ... report success at using lasers to dramatically sculpt the properties of materials without the production of any excess damaging heat. ...
The team found a "sweet spot" to get around this ... where the frequency of the laser is fine-tuned in such a way to markedly change the material's properties without imparting any unwanted heat. ...
The scientists also say they found an ideal material to demonstrate this method. The material, a semiconductor called manganese phosphorus trisulphide, naturally absorbs only a small amount of light over a broad range of infrared frequencies. For their experiments ... used intense infrared laser pulses, each lasting about 10-13 seconds, to rapidly change the energy of electrons inside the material. As a result, the material shifted from a highly opaque state to a highly transparent one for certain colors of light. Even more critical, the researchers say, is that the process is reversible. When the laser turns off, the material instantly goes back to its original state completely unscathed. ..."
The scientists also say they found an ideal material to demonstrate this method. The material, a semiconductor called manganese phosphorus trisulphide, naturally absorbs only a small amount of light over a broad range of infrared frequencies. For their experiments ... used intense infrared laser pulses, each lasting about 10-13 seconds, to rapidly change the energy of electrons inside the material. As a result, the material shifted from a highly opaque state to a highly transparent one for certain colors of light. Even more critical, the researchers say, is that the process is reversible. When the laser turns off, the material instantly goes back to its original state completely unscathed. ..."
From the abstract:
"Strong periodic driving with light offers the potential to coherently manipulate the properties of quantum materials on ultrafast timescales. Recently, strategies have emerged to drastically alter electronic and magnetic properties by optically inducing non-trivial band topologies emergent spin interactions and even superconductivity. However, the prospects and methods of coherently engineering optical properties on demand are far less understood1. Here we demonstrate coherent control and giant modulation of optical nonlinearity in a van der Waals layered magnetic insulator, manganese phosphorus trisulfide (MnPS3). By driving far off-resonance from the lowest on-site manganese d–d transition, we observe a coherent on–off switching of its optical second harmonic generation efficiency on the timescale of 100 femtoseconds with no measurable dissipation. ... Our approach can be applied to a broad range of insulating materials and could lead to dynamically designed nonlinear optical elements."
Giant modulation of optical nonlinearity by Floquet engineering (no public access)
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