Spin-noise spectroscopy of atoms and molecules

• Applicant: Dr. Sergei Lukashov, Ph.D.
• Subject Area: Optics, Quantum Optics and Physics of Atoms, Molecules and Plasmas
• Term: since 2023
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 534430225

Traditional methods of atomic and molecular spectroscopy, from electronic spin resonance to optical absorption or transmission, are based on the principle of the resonance response of the object. However, certain resonances can be observed also by monitoring the excess fluctuations of the medium’s parameters, susceptibility, magnetization, birefringence, etc. Today, non-perturbative measurements are becoming mainstream methods. Optical spin-noise spectroscopy with direct measurement of spin noise by Faraday rotation is one of them. Today spin-noise spectroscopy was already applied to monitor spin dynamics in gas phase atomic, quantum wells, and single quantum dots in semiconductors. This method can be used as a probe of collisional dynamics, spatial properties, quantum state correlations, and entanglement. However, molecules have not been studied by the spin-noise spectroscopy method. The main goal of this proposal is to demonstrate the possibilities of the noise Faraday rotation and Raman spectroscopy with application to atomic and molecular species. Both the traditional spin-noise spectroscopy method and high-frequency, stimulated, and two-color variants will be applied to the atoms and diatomic molecules in the gas phase. In addition to warm vapors of atoms and homonuclear/heteronuclear diatomic molecules in their ground and excited electronic states, we will study cooled molecular systems in cryo-buffer cells and magnetic traps.

• DFG Programme: WBP Position