Kim Donghwan, Heller Eric J
Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA.
Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138, USA.
Phys Rev Lett. 2022 May 20;128(20):200402. doi: 10.1103/PhysRevLett.128.200402.
A potential for propagation of a wave in two dimensions is constructed from a random superposition of plane waves around all propagation angles. Surprisingly, despite the lack of periodic structure, sharp Bragg diffraction of the wave is observed, analogous to a powder diffraction pattern. The scattering is partially resonant, so Fermi's golden rule does not apply. This phenomenon would be experimentally observable by sending an atomic beam into a chaotic cavity populated by a single mode laser.
通过在所有传播角度周围对平面波进行随机叠加，构建了一种二维波传播的可能性。令人惊讶的是，尽管缺乏周期性结构，但仍观察到了波的尖锐布拉格衍射，类似于粉末衍射图案。散射部分是共振的，因此费米黄金定则不适用。通过将原子束送入由单模激光填充的混沌腔中，这种现象在实验上是可观测的。
