摘要The spontaneous evolution from ultracold Rydberg atoms to plasma is investigated in a caesium MOT by using the method of field ionization. The plasma transferred from atoms in different Rydberg states (n=22--32) are obtained experimentally. Dependence of the threshold time of evolving to plasma and the threshold number of initial Rydberg atoms on the principal quantum number of initial Rydberg states is studied. The experimental results are in agreement with hot--cold Rydberg--Rydberg atom collision ionization theory.
Abstract:The spontaneous evolution from ultracold Rydberg atoms to plasma is investigated in a caesium MOT by using the method of field ionization. The plasma transferred from atoms in different Rydberg states (n=22--32) are obtained experimentally. Dependence of the threshold time of evolving to plasma and the threshold number of initial Rydberg atoms on the principal quantum number of initial Rydberg states is studied. The experimental results are in agreement with hot--cold Rydberg--Rydberg atom collision ionization theory.
[1] Killian T C, Kulin S, Bergeson S D , Orozco L A and Rolston S L1999 Phys. Rev. Lett. 83 4776 [2] Kulin S, Killian T C, Bergeson S D and Rolston S L 1999 Phys. Rev. Lett. 85 318 [3] Killian T C, Lim M J, Kulin S, Dumke R, Bergeson S D and Rolston SL 2001 Phys. Rev. Lett. 86 759 [4] Robinson M P, Laburthe-Torla B, Noel M W, Gallagher T F and PilletP 2000 Phys. Rev. Lett. 85 4466 [5] Pohl T, Pattard T and Rost J M 2003 Phys. Rev. A 68 010703 [6]Gallagher T F, Pillet P, Robinson M P, Laburthe-Tolra B and Noel M W2003 J. Opt. Soc. Am. B 20 1091 [7] Vogt T, Viteau M, Zhao J M, Chotia A, Comparat D and Pillet P 2006 Phys. Rev. Lett. 97 083003 [8] Vitrant G, Raimond J M, Gross M and Haroche S 1982 J.Phys. B 15 49 [9] Li W H, Noel M W, Robinson M P, Tanner P J, Gallagher T F, ComparatD, Tolra B L, Vanhaecke N, Vogt T, Zahzam N, Pillet P and Tate D A 2004 Phys. Rev. A 70 042713 [10] Robicheaux F and Hanson J D 2003 Phys. Plasmas 10 2217 [11] Gupta P, Laha S, Simien C E, Gao H, Castro J and Killian T C 2007 Phys. Rev. Lett. 99 075005