Quantum Zeno effect in atomic spin-exchange collisions

Wei Xiao, Teng Wu, Xiang Peng +1 more

Spin-exchange collisions among alkali-metal atoms affect the coherence time and gyromagnetic ratio of atoms by redistributing the ground-state population. We theoretically study the interactions between magnetic fields and atoms in the presence of spin-exchange collisions. Using the modified Bloch equations derived from the density-matrix equation in a low spin-polarization limit, we obtain explicit formulas describing the role of spin-exchange collisions in the interactions between atoms and magnetic fields, especially the nonresonant radio-frequency fields, which are widely used to manipulate atoms. The results derived from these equations agree well with density-matrix simulations and previous experimental results, and provide a simple and precise way to quantitatively analyze the effect of spin-exchange collisions on atoms. Our paper is helpful to gain physical insight into the spin-exchange collisions and optimize the performance of atom-based precision measurement instruments.

Saverio Pascazio, Mikio Namiki, G. Badurek +1 more

Wei Wu

Sergei P. Dmitriev, N. A. Dovator, Victor A. Kartoshkin +1 more

Abstract Spin exchange is one of the effective processes for obtaining spin-polarized atoms. Such mechanism of spin polarization is usually used to transmit and observe the longitudinal (along magnetic field) component magnetization of atoms. However, spin-exchange collisions can also lead to the transfer of the transverse component of magnetization, which occurs when the atoms involved in the collisions are exposed to an alternating resonant magnetic field. This article describes experiments to observe the transmission of transverse magnetization between alkali metal atoms 133Cs and 85Rb in spin-exchange collisions. The calculation of the spin exchange in a mixture of Cs and Rb under magnetic resonance conditions gave a qualitative agreement with the experimental results.

Almut Beige, Gerhard C. Hegerfeldt, Dirk G. Sondermann

Sergei P. Dmitriev, N. A. Dovator, E. N. Pestov +2 more

An experiment on the observation of the effect of transmitting the transverse spin magnetization in spin-exchange collisions of cesium atoms with optically aligned rubidium atoms is described.