Collision-Sensitive Spin Noise

Collision phenomena are ubiquitous and of importance in determining the microscopic structures intermolecular interactions atoms molecules. The existing approaches mostly based on atomic or molecular scatterings, which hindered by inconvenience using ultra-high vacuum low temperature systems. Here we demonstrate a new spin-noise spectroscopic approach measuring optical polarization rotation noise probe light, operates with simple apparatus ambient conditions. Our features tens gigahertz bandwidth one part-per-million resolution, outperforming techniques. Enabled technique, observe collision-induced spin alkali atoms, precisely determine key collision parameters, such as diameter, well depth, dominant interaction type. work provides tool to study broad range under