Department of Materials Science and Engineering, Stanford University, Stanford, California 94035, USA.
Phys Rev Lett. 2012 Jun 29;108(26):267403. doi: 10.1103/PhysRevLett.108.267403. Epub 2012 Jun 27.
We present the first single-shot images of ferromagnetic, nanoscale spin order taken with femtosecond x-ray pulses. X-ray-induced electron and spin dynamics can be outrun with pulses shorter than 80 fs in the investigated fluence regime, and no permanent aftereffects in the samples are observed below a fluence of 25 mJ/cm(2). Employing resonant spatially muliplexed x-ray holography results in a low imaging threshold of 5 mJ/cm(2). Our results open new ways to combine ultrafast laser spectroscopy with sequential snapshot imaging on a single sample, generating a movie of excited state dynamics.
我们首次利用飞秒 X 射线脉冲拍摄到了铁磁纳米级自旋有序的单张图像。在研究的强度范围内，短于 80fs 的脉冲可以超越 X 射线诱导的电子和自旋动力学，在强度低于 25mJ/cm²的情况下，样品中没有观察到永久的后效。采用共振空间复用 X 射线全息术，成像阈值低至 5mJ/cm²。我们的结果为超快激光光谱学与单个样品上的顺序快照成像相结合开辟了新途径，生成了激发态动力学的电影。
