Tightly trapped highly excited Rydberg atom in dipole-quadrupole potential landscape

• Published in: Journal of modern optics Vol. 66; no. 17; pp. 1725 - 1735
• Main Author: Mashhadi, Leila
• Format: Journal Article
• Language: English
• Published: Abingdon Taylor & Francis 07.10.2019; Taylor & Francis Ltd
• Subjects: AC Stark shift; Angular momentum; Dipole-quadrupole trap; Dipoles; Excitation; Gaussian beams (optics); Ground state; Laguerre-Gaussian beam; Laser beams; Quadrupoles; Quantum phenomena; qudit; Rydberg excitation; Rydberg states; Stiffness; Trapping
• ISSN: 0950-0340; 1362-3044
• DOI: 10.1080/09500340.2019.1660814

In this paper, coherent Rydberg excitation of a single four-level atom in tightly confining trap so-called 'far-off-resonance optical dipole-quadrupole trap' (FORDQT) by considering Laguerre Gaussian (LG) beams spatial features is demonstrated. The self-trapping potential results from the position dependent differential AC Stark shift of the ground state and Rydberg state in the effective quadrupole Rydberg excitation. By introducing the effective stiffness of the FORDQT potential in terms of the key parameters of the first and Rydberg excitation laser beams, a technique to obtain sub-micron localization of Rydberg excitation is explored. The complete matched trapping potential of the ground state and Rydberg state near the center of the trap maintains the coherence of the Rydberg excitation. Transfer of optical orbital angular momentum from the LG-beam to the Rydberg-state via localized effective quadrupole excitation process paves the way for implementation of high fidelity qudit gates in high dimensional quantum information process.