Rydberg atoms in microwave fields

Kazuki Komatsu, A. Takamine, Yoshihiro MIZUGAI +1 more

We report theoretical study on ionization suppression of Rydberg atom by bichromatic microwave field.In the framework of one-dimensional classical model we find that with the monochromatic microwave field of (angular) frequency 2 and amplitude 2F one-dimensional Rydberg atom is ionized, while adding the second microwave field of frequency  and amplitude F to the atom subjected to the first microwave field prohibits ionization of the Rydberg atom in case Kepler frequency of the Rydberg atom excited in the state of principal quantum number n, 1/n 3 , nearly matches K/4( +2) with K = 1.

Thomas F. Gallagher

Yue Cui, Feng-Dong Jia, Jianhai Hao +13 more

We demonstrate the use of an auxiliary microwave field to extend the bandwidth sensitivity of Rydberg-atom-based microwave electrometry. Electromagnetically induced transparency (EIT) and Autler-Townes (AT) splitting in Rydberg atom microwave electrometry provide advantageous sensitivity for the resonant detection of microwave (MW) fields because the Stark shift of the target Rydberg state takes the linear form of AT splitting. However, the sensitivity is reduced by several orders of magnitude for detuned MW fields because the Stark shift of the target Rydberg state depends on a weak nonlinear effect. We show that the auxiliary microwave field with appropriate Rabi frequency or detuning could shift the atomic energy levels to bring a particular Rydberg-Rydberg transition of interest for microwave sensing into resonance with the target microwave field. Using the atomic superheterodyne method, we verified the general method that regulates Rydberg energy levels using an auxiliary microwave field. The experimental results of this study confirm that this technique works efficiently for detecting microwave fields detuned by up to 100 MHz from resonance with the field-free Rydberg-Rydberg transition used for sensing. The measurement sensitivity of the detuned target field is increased by a factor of 10 compared with that achieved without the application of the auxiliary dressing field.

Michio Takami, H. Maeda, Yukari Matsuo +3 more

Yuhan Wang, Feng-Dong Jia, Jianhai Hao +9 more

A Rydberg atom-based mixer has opened up a new method to characterize microwave electric fields such as the precise measurement of their phase and strength. This study further demonstrates, theoretically and experimentally, a method to accurately measure the polarization of a microwave electric field based on a Rydberg atom-based mixer. The results show that the amplitude of the beat note changes with the polarization of the microwave electric field in a period of 180 degrees, and in the linear region a polarization resolution better than 0.5 degree can be easily obtained which reaches the best level by a Rydberg atomic sensor. More interestingly, the mixer-based measurements are immune to the polarization of the light field that forms the Rydberg EIT. This method considerably simplifies theoretical analysis and the experimental system required for measuring microwave polarization using Rydberg atoms and is of interest in microwave sensing.

Leo Moorman, Peter M. Koch