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Project 2.3: Theoretical Studies of Rydberg Atoms, Interaction with Ground-state Atoms and Interference in External Fields


           This research project aims at analyzing the theoretical studies of quantum mechanics related to the Rydberg-state rubidium atoms. The elements of group 1, such as hydrogen, sodium or rubidium, contain only one electron in the outermost shell. Upon stimulation of the electron into the high energy level of n=137, for example, it is pushed off over one micron far from the nucleus, making the Rydberg-state atom larger, compared with the size of 1 angstrom in the normal state. A distance away from the nucleus reduces the attractive force but increases sensitivity of an interaction with external fields. This tremendously enhances physical properties compared with other normal atoms like dipole moment property with 100 times of values that are higher than normal. The research conducted in 2015 titled in “Measurement and Numerical Calculation of Rubidium Rydberg Stark Spectra” by Grimmel et al. [1], studied and did an experiment in the quantum theory regarding interactions between the Rydberg atoms and the electric fields so called Stark Effect. This study is a good primary tester in developing the computer program and numerical calculation as the base for more complicated studies called “butterfly Rydberg molecules” as shown in Figure 2.3.1. Besides, Niederprum et. al. [2] was able to produce special molecules in the laboratory which is the chemical bond between rubidium atoms in the Rydberg state and rubidium atoms in the ground state to generate the molecules with electron diffusion of butterfly-wing shape. The life-time of these molecules can last around tens of microseconds.



Figure 2.3.1 Radial electron density of a butterfly molecule [2].


            As a part of the sub-research program on Innovative Quantum Physics for Oil and Gas Exploration, this research project mainly focuses on the theoretical studies through applications of quantum mechanics for the study of rubidium atoms by laser stimulation into the high energy state called the Rydberg state. These atoms can interact with external fields or coexist with another ground-state atom and has other interesting behaviors including quantum wave and interference with further applications as the high sensitivity tool for the earth’s gravity measurement. It also promises the potential for mapping the oil resources or economic minerals. The purposes of this research are as follows:
                       1) To study the physical properties of Rydberg atoms and interactions with ground-state atoms;
                       2) To study the dynamics of atoms in the external fields; and
                       3) 3) To study the interference of Rydberg atoms at the near absolute zero temperature for measuring the earth’s gravitational acceleration.



[1] J. Grimmel, et al., “Measurement and Numerical Calculation of Rubidium Rydberg Stark Spectra”, New Journal of Physics 17.5(2015)053005.
[2] T. Niederprum, et al., “Observation of Pendular Butterfly Rydberg Molecules”, Nature Communications 7(2016).


Principal Investigator: Dr. Teepanis Chachiyo 1)
Collaborator: Dr. Hathaithip Chachiyo 2)
Affiliated Institutes: 1) Department of Physics, Faculty of Science, Naresuan University, 2) Department of Biology, Faculty of Science, Naresuan University