Long range dipole-dipole interaction in atomic vapors probed by double-quantum two-dimensional coherent spectroscopy

• Published in: arXiv.org 2018-11
• Main Authors: Yu, Shaogang, Titze, Michael, Zhu, Yifu, Liu, Xiaojun, Li, Hebin
• Format: Article
• Language: English
• Subjects: Atomic radius; Cold atoms; Color centers; Diamonds; Dipole interactions; Many body problem; Potassium; Quantum dots; Rubidium; Spectrum analysis
• ISSN: 2331-8422
• DOI: 10.48550/arxiv.1811.07963

Optical double-quantum two-dimensional coherent spectroscopy (2DCS) was implemented to probe interatomic dipole-dipole interactions in both potassium and rubidium atomic vapors. The dipole-dipole interaction was detected at densities of \(4.81 \times 10^8\) cm\(^{-3}\) and \(8.40 \times 10^9\) cm\(^{-3}\) for potassium and rubidium, respectively, corresponding to a mean interatomic separation of 15.8 \(\mu\)m or \(3.0\times 10^5a_0\) for potassium and 6.1 \(\mu\)m or \(1.2\times 10^5a_0\) for rubidium, where \(a_0\) is the Bohr radius. We report the lowest atomic density at which dipole-dipole interactions are detected. The experimental results confirm the long range nature of the dipole-dipole interaction which is critical for understanding many-body physics in atoms/molecules. The long range interaction also has implications in atom-based applications involving many-body interactions. Additionally, we demonstrated that double-quantum 2DCS is sufficiently sensitive to probe dipole-dipole interaction at densities that can be achieved with cold atom in a magneto-optical trap, paving the way for double-quantum 2DCS studies of cold atoms and molecules. The method can also open a new avenue to study long-range interactions in solid states systems such as quantum dots and color centers in diamonds.