Energy Levels of Atoms in an Electric Field

Weimin Ruan, Yingyun Zhang, Zhigang Feng +3 more

Limited by the discontinuity of atomic energy level, using Rydberg atoms we can only measure the discrete microwave electric field in the actual measurement, which greatly restricts their practical applications. In this paper, we adjust the energy level of the Rydberg atoms by adding LO(Local Oscillator) field. The added LO field can shift the energy level of the Rydberg atoms. The shift is controlled by the frequency and the power of the LO field. Using this method we achieved the measurement of the continuous-frequency field based on Rubidium(87Rb) Rydberg atoms.

Attilio Rigamonti, P. Carretta

Valentina Zhelyazkova, S. D. Hogan

We present the results of experiments demonstrating the spectroscopic detection of Förster resonance energy transfer from NH3 in the X1A1 ground electronic state to helium atoms in 1sns 3S1 Rydberg levels, where n = 37 and n = 40. For these values of n, the 1sns 3S1 → 1snp 3PJ transitions in helium lie close to resonance with the ground-state inversion transitions in NH3 and can be tuned through resonance using electric fields of less than 10 V/cm. In the experiments, energy transfer was detected by direct state-selective electric field ionization of the 3S1 and 3PJ Rydberg levels and by monitoring the population of the 3DJ levels following pulsed microwave transfer from the 3PJ levels. Detection by microwave spectroscopic methods represents a highly state selective, low-background approach to probing the collisional energy transfer process and the environment in which the atom-molecule interactions occur. The experimentally observed electric-field dependence of the resonant energy transfer process, probed both by direct electric field ionization and by microwave transfer, agrees well with the results of calculations performed using a simple theoretical model of the energy transfer process. For measurements performed in zero electric field with atoms prepared in the 1s40s 3S1 level, the transition from a regime in which a single energy transfer channel can be isolated for detection to one in which multiple collision channels begin to play a role has been identified as the NH3 density was increased.

Attilio Rigamonti, P. Carretta

Yurii V. Dumin

Abstract Splitting the energy levels of a hydrogen-like atom by the electric field nonuniform at the atomic scale is studied. This situation is important for the multi-level treatment of the phenomenon of Rydberg blockade (Dumin Y V 2014 J. Phys. B: At. Mol. Opt. Phys. 47 175502 ). An explicit formula for the energy levels is derived. A typical value of the energy shift by the electric field gradient turns out to be proportional to the fourth power of the principal quantum number (i.e. the square of atomic size), as would be expected from a qualitative consideration. Finally, the fine spatial structure of the Rydberg blockade is analyzed when the electric-field-gradient term plays the dominant role, and the results are compared with the experimental data.

Attilio Rigamonti, P. Carretta