Coherence and Quantum Optics VI pp 1243-1247 | Cite as

# Macroscopic Quantum Jumps from a Two-Atom System

## Abstract

We present an analysis of the macroscopic quantum jumps (MQJ) [1,2,4] that can be produced when two identical two-level atoms separated by a distance *d* are irradiated by a laser having wavelength λ_{0}, with λ_{0} » *d*. The laser is resonant with the same ground to excited-state transition in each atom. The problem is conveniently described in terms of the eigenstates [5] of the two-atom system in the absence of any applied field (Fig.1). Denoting the ground and excited states of atom *i*(*i* = 1,2) by | gi > and | *e* _{ i } >, respectively, the appropriate eigenstates are given by | *E* >=| *e* _{1} *e* _{2} >, | *S* >= 1/\(\sqrt 2 \)
(|*e* _{1} *g* _{2} > + | *g* _{ 1 } *e* _{2} >), | *G* >=| *g* _{1} *g* _{2}
> and | *A*> = 1\(\sqrt 2 \)
(| *e* _{1} *g* _{2} > − | *g* _{1} *e* _{2} >); states | *E* >, | *S* > and | *G* > are symmetric and state | *A* > is antisymmetric on interchange of the atoms. Energy levels of states | *S* > and | *A* > are shifted from those of the non-interacting two-atom system by an amount *V*. For λ_{0} » *d*, the antisymmetric state has a small, but nonvanishing decay rate, Γ_{ A } ≅ (2π*d*/ λ_{0})^{2} Γ/5 while the symmetric state decays with a rate Γ_{ S } ≅ 2Γ (Γ = decay rate of a single atom). For the level scheme of Fig. 1, such decay rates lend themselves to the possibility of observing MQJ when the system is pumped by an external field.

## Keywords

Laser Field Rabi Frequency Pump Field Antisymmetric State Incoherent Pump## Preview

Unable to display preview. Download preview PDF.

## References

- [1]H.Dehmelt, Bull. Am. Phys. Soc. 20, 60 (1975).Google Scholar
- [2]R.J.Cook and H.J.Kimble, Phys. Rev. Lett.,vol. 54, 1023 (1985); H.J.Kimble, R.J.Cook, and A.L.Wells, Phys. Rev. A, vol. 34, 3190 (1986).Google Scholar
- [3]A.Schenzle, R.G.Devoe, and R.G.Brewer, Phys. Rev. A, vol.33, 2127 (1986); J.Javanainen, Phys. Rev. A, vol. 33, 2121 (1986).Google Scholar
- [4]W.Nagourney, J.Sandberg, and H.Dehmelt, Phys. Rev. Lett. 56, 2797 (1986); T.Sauter, W.Neuhauser, R.Blatt, and P.E.Toschek, Phys. Rev. Lett. 57, (1986); J.C.Bergquist, R.G.Hulet, W.M.Itano, and D.J.Wineland, Phys. Rev. Lett. 57, 1699 (1986).Google Scholar
- [5]R.H.Dicke, Phys. Rev., vol. 93, 99 (1954); R.H.Lehmberg, Phys. R.v. A, vol. 2, 889 (1970)Google Scholar
- [6]P.Zoller, M.Marte, and D.F.Walls, Phys. Rev: A, vol. 35, 198 (1987); C.Cohen- Tannoudji and J.Dalibard, Europhys. Lett. 1, 441 (1986).Google Scholar
- [7]M.Lewenstein and J.Javanainen, Phys. Rev. Lett., vol. 59, 1289 (1987).CrossRefGoogle Scholar
- [8]C.Cohen-Tannoudji and S.Reynaud, J. Phys. B 10, 345 (1977).CrossRefGoogle Scholar
- [9]G.S.AgarwalQuantum Optics, Springer Tracts in Modern Physics, vol. 70. edited by G.T.Hahler (Springer-Verlag, New York, 1974).Google Scholar