Microwave spectroscopy assisted by electromagnetically induced transparency near natural Förster resonance on Rubidium

Abstract

In this work, we precisely measure the transition energies between the Rydberg state n${\text{D}}_{5/2}$ to the nearby Rydberg states $(\e{n}+2)\text{P}_{3/2}$, $(\e{n}-2)\text{F}_{7/2}$ for the range $41\leq \e{n}\leq46$. This was done by carrying out microwave spectroscopy via Electromagnetically Induced Transparency (EIT) in a room temperature vapor reference cell of Rubidium, which is similar to the experimental approach followed by Li et al. [Results in Physics \textbf{29}, 104728 (2021)]. This range is interesting because there is a quasi Förster resonance between the atomic pair $43{\text{D}}_{5/2}+43{\text{D}}_{5/2}$ and $45{\text{P}}_{3/2}+41{\text{F}}_{7/2}$. We compared the obtained results with numerically calculated transition energies based on previously tabulated quantum defect numbers by various research groups using both hot and ultra-cold atomic samples. Our data are more consistent with measurements made within ultra-cold atomic systems [Phys. Rev. A \textbf{67}, 052502 (2003), Phys. Rev. A \textbf{74}, 054502 (2006)].