Speaker: Dr. Kourosh Afrousheh
Post-doctoral fellow, Rowland Institute at Harvard
Harvard University, Cambridge, US
Local host in Shahid Beheshti University: Prof. Seyed Hassan Tavasoli
Local host in University of Isfahan: Prof. Mahmood Soltanolkotabi
Title: Dipole-dipole interactions between laser cooled highly excited atoms
(1) Time: Wednesday, Dec 27, 2006
Location: Laser and Plasma Research Institute, Shahid Beheshti University, Tehran
(2) Time: Tuesday, Jan 2, 2007
Location: Department of Physics, University of Isfahan, Isfahan
Abstract:
Having large transition dipole moments, highly excited Rydberg atoms may strongly interact through electric dipole-dipole coupling. Therefore, excitation to Rydberg states allows one to turn on strong interactions between atoms which would otherwise be negligible. Thus, temporary excitation to Rydberg states has been proposed for implementing elements of quantum information processing using cold neutral atoms [1]. For example, it has been proposed that a single excited Rydberg atom in a cloud may block further resonant excitation due to the dipole-dipole interaction, a process known as “dipole blockadeâ€[2]. To investigate this idea, we have experimentally studied the dipole-dipole interaction between translationally cold Rydberg atoms excited in a magneto-optical trap [3]. We have used microwave spectroscopy to probe interatomic interactions. We have also demonstrated that resonant electric dipole-dipole interactions between cold Rydberg atoms are partially suppressed by DC magnetic fields [4]. In another experiment we have used electric field induced resonant energy transfer between cold Rydberg atoms to determine the ng-series quantum defect.
In this talk, I will briefly explain our experimental setup for cold Rydberg atom studies followed by the discussion of the results of the experiments. Then, I will present my current research that is focused primarily on studying the interaction of cold Rydberg atoms with terahertz radiation. The goal of this experiment is to develop techniques that will be used to bring antihydrogen atoms from currently produced mixture of highly excited states to ground state for further spectroscopic studies.
References:
[1] D. Jaksch et al., Phys. Rev. Lett. 85, 2208 (2000).
[2] M. D. Lukin et al., Phys. Rev. Lett. 87, 037901 (2001).
[3] K. Afrousheh et al., Phys. Rev. Lett. 93, 233001 (2004).
[4] K. Afrousheh et al., Phys. Rev. A 73, 063403 (2006).