## A Saturnian atom

Optics Express, Vol. 1, Issue 7, pp. 221-228 (1997)

http://dx.doi.org/10.1364/OE.1.000221

Acrobat PDF (609 KB)

### Abstract

In Bohr’s original planetary model of the atom the electron moves along orbits of special geometric simplicity. While wave mechanics precludes the idea that a physical path could be ascribed to the electron, a classical or planetary atom can still be envisaged in which the electronic wavepacket neither spreads nor disperses as its center moves along the Kepler orbit, and this orbit is confined to a single plane in space. We show theoretically how an electronic wavepacket may be localized in this fashion in a similar way to ion confinement in a Penning trap. Because external fields are needed to keep the packet confined, a more fitting analogy than a planetary orbit is the motion of a charged dust grain in one of the rings of a giant planet such as Saturn.

© Optical Society of America

^{11. E. Rutherford, Phil. Mag. 21, 669 (1911). [CrossRef] }considered Nagaoka’s Saturnian atom

^{22. E. Nagaoka, “Kinetics of a system of particles illustrating the line and the band spectrum and the phenomena of radioactivity”, Phil. Mag. 7, 445–455 (1904). [CrossRef] }which consisted of rings of rotating electrons.

^{2–42. E. Nagaoka, “Kinetics of a system of particles illustrating the line and the band spectrum and the phenomena of radioactivity”, Phil. Mag. 7, 445–455 (1904). [CrossRef] }Although wave mechanics forced the abandonment of the idea that a physical path could be ascribed to the electron, a classical or

*planetary*atom can still be envisaged in which:

*(i)*the electronic wavepacket neither spreads nor disperses as it moves along a Kepler orbit,

*(ii)*this orbit is confined to a single plane in space. Physically, this atom is a rotating giant dipole.

^{55. G. Raithel, M. Fauth, and H. Walther, “Atoms in strong crossed electric and magnetic fields: Evidence for states with large electric-dipole moments”, Phys. Rev. A 47, 419–440 (1991). [CrossRef] }We show theoretically how this can be achieved using external fields similar to ion or electron confinement in the Penning trap

^{66. H. Dehmelt, “Nobel Prize Lecture”, Rev. Mod. Phys. 62, 525–531 (1992). [CrossRef] }except that the motion is associated with a genuine harmonic

*minimum*in the effective potential. The dynamics resembles the motion of a charged dust grain in one of the ethereal rings of a giant planet,

*e.g.*, the Gossamer Ring of Jupiter or Saturn’s F, G and E rings

^{77. J. A. Burns and L. Schaffer, “Orbital evolution of circumplanetary dust by resonant charge variations”, Nature 337, 340–343 (1989). [CrossRef] ,88. L. Schaffer and L. Burns, “Charged dust in planetary magnetospheres: Hamiltonian dynamics and numerical simulations for highly charged grains”, J. Geophys. Res. 99, 17211–17223 (1994). [CrossRef] }, and in this sense, the system may be considered to be a one-electron Saturnian atom.

*i.e.*, a Rydberg atom.

^{99. T. F. Gallagher, Rydberg Atoms, (Cambridge University Press, Cambridge, 1994). [CrossRef] }A particular goal has been the creation of non-spreading electronic wavepackets or coherent states that move along Keplerian orbits in a similar fashion to an electron in Bohr’s planetary atom.

^{10–1210. M. Nauenberg, “Quantum wave packets on Kepler elliptic orbits”, Phys. Rev. A 40, 1133–1136 (1989). [CrossRef] [PubMed] }However, the best that has been accomplished are atoms in which the spreading of the wavepacket is localized on a Kepler orbit—

*i.e.*, radial but not angular confinement.

^{10–1210. M. Nauenberg, “Quantum wave packets on Kepler elliptic orbits”, Phys. Rev. A 40, 1133–1136 (1989). [CrossRef] [PubMed] }In these studies the strategy has often been to work at very high quantum numbers for which the local energy spacings are approximately constant and use laser excitation to form a spatially localized superposition of atomic states.

^{13–1713. P. Fu, T. J. Scholz, J. M. Hettema, and T. F. Gallagher, “Ionization of Rydberg atoms by circularly polarized microwave field”, Phys. Rev. Lett. 64, 511–514 (1990). [CrossRef] [PubMed] }and the Restricted Three-Body Problem

^{1818. V. Szebehely, Theory of orbits: The restricted problem of three bodies, (Academic, New York and London, 1967).}led us

^{1919. D. Farrelly and T. Uzer, “Ionization mechanism of Rydberg atoms in a circulary polarized microwave field”,Phys. Rev. Lett. 74, 1720–1723 (1995). [CrossRef] [PubMed] }and Bialynicki-Birula, Kalinski and Eberly (BKE)

^{2020. I. Bialynicki-Birula, M. Kaliński, and J. H. Eberly, “Lagrange equilibrium points in celestial mechanics and nonspreading wave packets for strongly driven Rydberg electrons”, Phys. Rev. Lett. 73, 1777–1780 (1994). [CrossRef] [PubMed] }to discover independently that in the CP problem, stable equilibrium points exist that are analogous to the Lagrangian equilibrium points in celestial mechanics.

^{1818. V. Szebehely, Theory of orbits: The restricted problem of three bodies, (Academic, New York and London, 1967).}This analogy led BKE to expect that wave packets launched from the equilibrium points (analogs of the so-called Lagrange points

*L*

_{4}and

*L*

_{5}) would orbit the nucleus without spreading. The Lagrange equilibrium points are stable maxima that support the Trojan asteroids of Jupiter, making the term “Trojan” wave packet appropriate for these states.

^{21–2321. M. Kaliński, J. H. Eberly, and I. Bialynicki-Birula,“Numerical observation of stable field supported Rydberg wave packets”, Phys. Rev. A 52, 2460–2463 (1995). [CrossRef] }However, the analogy between Rydberg atoms and planetary systems turns out to be fruitful but not perfect since the finite size of Planck’s constant imposes an absolute scale on the atomic problem.

^{2424. D. Farrelly, E. Lee, and T. Uzer, Comment on “Lagrange equilibrium points in celestial mechanics and nonspreading wave packets for strongly driven Rydberg electrons”, Phys. Rev. Lett. 75, 972 (1995). [CrossRef] [PubMed] ,2525. I. Bialynicki-Birula, M. Kaliński, and J. H. Eberly, Reply to Ref. 22, Phys. Rev. Lett. 75, 973 (1995). [CrossRef] [PubMed] }The atomic analogs of these points are stable only over a limited range of parameters, and placing a finite-size minimum uncertainty wave packet at such an equilibrium point becomes a delicate balancing act.

^{2121. M. Kaliński, J. H. Eberly, and I. Bialynicki-Birula,“Numerical observation of stable field supported Rydberg wave packets”, Phys. Rev. A 52, 2460–2463 (1995). [CrossRef] }suffers very little, if any, of the dispersion that plagued their original wave packet because it nestles inside the effective potential of the CP field. Following the early discovery of similar Floquet states anchored to stable islands in the classical phase space of the linearly polarized microwave problem,

^{26–2726. A. Buchleitner and Thèse de doctorat, Université Pierre et Marie Currie, Paris, 1993 (unpublished).}Zakrzewski, Delande, and Buchleitner

^{2828. J. Zakrzewski, D. Delande, and A. Buchleitner,“Nonspreading electronic wave packets and conductance fluctuations”, Phys. Rev. Lett. 75, 4015–4018 (1995). [CrossRef] [PubMed] ,2929. D. Delande, J. Zakrzewski, and A. Buchleitner, “A wave packet can be a stationary state”, Europhys. Lett. 32, 107–112 (1995). [CrossRef] }have shown that it is possible to find eigenstates of the problem in a rotating frame that, being eigenstates, are immune to spreading. In the laboratory frame such eigenstates indeed orbit the nucleus without spreading. These states are neither wave packets nor coherent states in the sense of Schrödinger and will not mimic the harmonic oscillator coherent states; i.e. they are not minimum uncertainty wave packets since locally the equilibria in the CP problem are not harmonic.

^{3030. D. Farrelly, E. Lee, and T. Uzer, “Magnetic field stabilization of Rydberg wavepackets in a circulary polarized microwave field”, Phys. Lett. A 204, 359–372 (1995). [CrossRef] }Suggestions for the experimental preparation of these states can be found in the literature.

^{2929. D. Delande, J. Zakrzewski, and A. Buchleitner, “A wave packet can be a stationary state”, Europhys. Lett. 32, 107–112 (1995). [CrossRef] }

^{30–3430. D. Farrelly, E. Lee, and T. Uzer, “Magnetic field stabilization of Rydberg wavepackets in a circulary polarized microwave field”, Phys. Lett. A 204, 359–372 (1995). [CrossRef] }Associated with this minimum are the usual non-dispersive coherent states of the harmonic oscillator.

^{1111. A. O. Barut and B. W. Xu, “Non-spreading coherent states riding on Kepler orbits”, Helv. Phys. Act. 66, 712–720 (1993).}

*m*

_{e}=

*e*= 1) the energy for a hydrogen atom subjected to a circularly polarized microwave field and a magnetic field perpendicular to the plane of polarization is

*z*–direction and,

*ω*

_{c}=

*eB*/

*m*

_{e}

*c*is the cyclotron frequency,

*ω*

_{f}is the microwave field frequency and

*F*its strength. In a synodic frame rotating with the field frequency

*ω*

_{f}the Hamiltonian becomes

^{30–3430. D. Farrelly, E. Lee, and T. Uzer, “Magnetic field stabilization of Rydberg wavepackets in a circulary polarized microwave field”, Phys. Lett. A 204, 359–372 (1995). [CrossRef] }

*K*is the Jacobi constant

^{1818. V. Szebehely, Theory of orbits: The restricted problem of three bodies, (Academic, New York and London, 1967).}and the coordinates are now interpreted as being in the rotating frame.

*ω*

_{f}=

*ω*

_{c}/2—thereby eliminating the paramagnetic term—and a typical section through the resulting surface is shown in Fig. 1 for experimental parameters that are consistent with those that are currently (if not routinely) achievable. Note particularly the existence of a saddle point and an outer

*harmonic*minimum in the potential. The ground state (vacuum state) of the harmonic oscillator, being a coherent state, is our wave packet. In the laboratory frame the equilibrium at the minimum corresponds to a circular orbit in the plane and localization of the electron in this well produces a giant atomic dipole rotating at the microwave frequency in the

*x*-

*y*plane.

^{55. G. Raithel, M. Fauth, and H. Walther, “Atoms in strong crossed electric and magnetic fields: Evidence for states with large electric-dipole moments”, Phys. Rev. A 47, 419–440 (1991). [CrossRef] }For snapshots of its progress around its circular orbit see Fig.3 of Ref. 34

34. C. Cerjan, E. Lee, D. Farrelly, and T. Uzer, “Coherent states in a Rydberg atom: Quantum mechanics”, Phys. Rev. A **55**, 2222–2231 (1997). [CrossRef]

*z*= 0, with no component of velocity in the

*z*–direction, then it is guaranteed to remain in that plane (below the zero-field ionization limit the motion in the

*z*–direction is essentially harmonic around the minimum and uncouples form the planar motion). Thereby the system can be made to meet the criteria of a planetary atom—an electronic wave packet prepared in the well will move in a non-dispersive fashion along circular Keplerian orbits that lie in a plane perpendicular to the magnetic field axis.

*K*/

*ω*

_{f}/

*ω*

_{c}and

*ϵ*=

*F*/

*i.e.*non-dispersive) harmonic motion in the well. Quantum mechanically, such a state is destabilized by two decay mechanism: tunneling to the core through the potential barrier in Fig. 1 and radiative decay. Semiclassical estimates of the lifetime due to these mechanisms show them to be extremely long, which is not surprising in view of the classical nature of these states. Rigurous quantal calculation for the spontaneous decay of Trojan wave packets

^{3535. K. Hornberger and A. Buchleitner, “Spontaneous decay of nondispersive wave packets”, (to be published).,3636. Z. Bialynicki-Birula and I. Bialynicki-Birula, “Radiative decay of Trojan wave packets”, (to be published).}are in harmony with semiclassical estimates.

^{1818. V. Szebehely, Theory of orbits: The restricted problem of three bodies, (Academic, New York and London, 1967).,3737. G. W. Hill, Am. J. Math. 1, 5–128, (1878). [CrossRef] }

*still*possible to produce an outer well at large distances from the nucleus.

^{32–3432. A. F. Brunello, D. Farrelly, and T. Uzer, “Nonstationary, nondispersive wave packets in a Rydberg atom”, Phys. Rev. Lett. 76, 2874–2877 (1996). [CrossRef] [PubMed] }In this case the motion may be chaotic as shown in Fig. 4, but, provided tunneling is unimportant, the electron will be confined in the well by the curves of zero velocity for all values of

*K*below the saddle point. Extensive numerical simulations and stability analysis

^{3333. E. Lee, A. F. Brunello, and D. Farrelly, “Coherent states in a Rydberg atom: Classical mechanics”, Phys. Rev. A 55, 2203–2221 (1997). [CrossRef] }show that in the three-dimensional system, below the zero-field ionization limit, the electron may be confined similarly. Remarkably, even in these cases, when the electronic motion is mostly chaotic, the regular part of the phase space is, for relevant experimental parameters, still large enough (measured in ħ) to support states (see Fig. 2 of Ref. 32

32. A. F. Brunello, D. Farrelly, and T. Uzer, “Nonstationary, nondispersive wave packets in a Rydberg atom”, Phys. Rev. Lett. **76**, 2874–2877 (1996). [CrossRef] [PubMed]

33. E. Lee, A. F. Brunello, and D. Farrelly, “Coherent states in a Rydberg atom: Classical mechanics”, Phys. Rev. A **55**, 2203–2221 (1997). [CrossRef]

*maximum*in the zero velocity surface.

^{3030. D. Farrelly, E. Lee, and T. Uzer, “Magnetic field stabilization of Rydberg wavepackets in a circulary polarized microwave field”, Phys. Lett. A 204, 359–372 (1995). [CrossRef] }This point is similar to the equilibria

*L*

_{4}and

*L*

_{5}which are themselves

*maxima*in the restricted three body problem associated,

*e.g.*, with Jupiter’s Trojan asteroids.

^{3333. E. Lee, A. F. Brunello, and D. Farrelly, “Coherent states in a Rydberg atom: Classical mechanics”, Phys. Rev. A 55, 2203–2221 (1997). [CrossRef] }Like

*L*

_{4}and

*L*

_{5}, the atomic Lagrangian points are linearly stable over only a narrow range of parameters, although by fine tuning of parameters it may be possible to assemble non-dispersive wave packets localized around these maxima,

^{2020. I. Bialynicki-Birula, M. Kaliński, and J. H. Eberly, “Lagrange equilibrium points in celestial mechanics and nonspreading wave packets for strongly driven Rydberg electrons”, Phys. Rev. Lett. 73, 1777–1780 (1994). [CrossRef] [PubMed] }possibly by adding a magnetic field to enhance the stability of the maximum.

^{30–3430. D. Farrelly, E. Lee, and T. Uzer, “Magnetic field stabilization of Rydberg wavepackets in a circulary polarized microwave field”, Phys. Lett. A 204, 359–372 (1995). [CrossRef] }Experimental preparation of a coherent state in the well would proceed similarly but, by producing a

*minimum*, we have avoided delicate stability issues that are associated with equilibrium points that are maxima in an effective potential.

^{3838. R. Greenberg and D. R. Davis, “Stability at potential maxima: The L4 and L5 points of the Restricted Three-Body Problem”, Am. J. Phys. 46, 1068–1070, (1978). [CrossRef] }

34. C. Cerjan, E. Lee, D. Farrelly, and T. Uzer, “Coherent states in a Rydberg atom: Quantum mechanics”, Phys. Rev. A **55**, 2222–2231 (1997). [CrossRef]

^{3535. K. Hornberger and A. Buchleitner, “Spontaneous decay of nondispersive wave packets”, (to be published).,3636. Z. Bialynicki-Birula and I. Bialynicki-Birula, “Radiative decay of Trojan wave packets”, (to be published).}

^{88. L. Schaffer and L. Burns, “Charged dust in planetary magnetospheres: Hamiltonian dynamics and numerical simulations for highly charged grains”, J. Geophys. Res. 99, 17211–17223 (1994). [CrossRef] }to study the dynamics of a charged dust grain in an ethereal ring of a giant planet. They consider the planet’s gravitational field and assume a rotating magnetic dipole to model the planetary magnetosphere (effects due to planetary obliquity, drag, radiation pressure, dipole tilt, etc., are neglected). Inclusion of the effect of solar radiation pressure

^{3939. Deprit, in The Big Bang and George Lemaitre, edt. A. Berger, (Reidel, Dordrecht, 1984), pp. 151–180.}in this model gives a non-integrable Hamiltonian similar to Eq.(1) except that the magnetic field in Eq.(1) is homogeneous. Nevertheless, outer stable equilibrium points can also exist and in both systems stable motion is confined preferentially to a plane lying perpendicular to a privileged direction established by a rotation axis.

## Acknowledgments

## References

1. | E. Rutherford, Phil. Mag. |

2. | E. Nagaoka, “Kinetics of a system of particles illustrating the line and the band spectrum and the phenomena of radioactivity”, Phil. Mag. |

3. | N. Bohr, Phil. Mag. |

4. | M. Born, |

5. | G. Raithel, M. Fauth, and H. Walther, “Atoms in strong crossed electric and magnetic fields: Evidence for states with large electric-dipole moments”, Phys. Rev. A |

6. | H. Dehmelt, “Nobel Prize Lecture”, Rev. Mod. Phys. |

7. | J. A. Burns and L. Schaffer, “Orbital evolution of circumplanetary dust by resonant charge variations”, Nature |

8. | L. Schaffer and L. Burns, “Charged dust in planetary magnetospheres: Hamiltonian dynamics and numerical simulations for highly charged grains”, J. Geophys. Res. |

9. | T. F. Gallagher, |

10. | M. Nauenberg, “Quantum wave packets on Kepler elliptic orbits”, Phys. Rev. A |

11. | A. O. Barut and B. W. Xu, “Non-spreading coherent states riding on Kepler orbits”, Helv. Phys. Act. |

12. | J. A. Yeazell and C. R. Stroud, “Observation of fractional revivals in the evolution of a Rydberg atomic wave packet”, Phys. Rev. A |

13. | P. Fu, T. J. Scholz, J. M. Hettema, and T. F. Gallagher, “Ionization of Rydberg atoms by circularly polarized microwave field”, Phys. Rev. Lett. |

14. | C. H. Cheng, C. Y. Lee, and T. F. Gallagher, “Production of circular Rydberg states with circularly polarized microwave fields”, Phys. Rev. Lett. |

15. | M. Nauenberg, Comment on “Ionization of Rydberg states by a circularly polarized microwave field”, Phys. Rev. Lett. |

16. | M. Nauenberg, “Canonical Kepler map”, Europhys. Lett. |

17. | P. Kappertz and M. Nauenberg, “Circularly polarized microwave ionization of hydrogen”, Phys. Rev. A |

18. | V. Szebehely, |

19. | D. Farrelly and T. Uzer, “Ionization mechanism of Rydberg atoms in a circulary polarized microwave field”,Phys. Rev. Lett. |

20. | I. Bialynicki-Birula, M. Kaliński, and J. H. Eberly, “Lagrange equilibrium points in celestial mechanics and nonspreading wave packets for strongly driven Rydberg electrons”, Phys. Rev. Lett. |

21. | M. Kaliński, J. H. Eberly, and I. Bialynicki-Birula,“Numerical observation of stable field supported Rydberg wave packets”, Phys. Rev. A |

22. | M. Kaliński and J. H. Eberly, “Trojan wave packets: Mathieu theory and generation from circular states”, Phys. Rev. A |

23. | M. Kaliński and J. H. Eberly,“New states of hydrogen in a circulary polarized microwave field”, Phys. Rev. Lett. |

24. | D. Farrelly, E. Lee, and T. Uzer, Comment on “Lagrange equilibrium points in celestial mechanics and nonspreading wave packets for strongly driven Rydberg electrons”, Phys. Rev. Lett. |

25. | I. Bialynicki-Birula, M. Kaliński, and J. H. Eberly, Reply to Ref. 22, Phys. Rev. Lett. |

26. | A. Buchleitner and Thèse de doctorat, Université Pierre et Marie Currie, Paris, 1993 (unpublished). |

27. | A. Buchleitner and D. Delande, “Nondispersive electronic wave packets in multiphoton processes”, Phys. Rev. Lett. |

28. | J. Zakrzewski, D. Delande, and A. Buchleitner,“Nonspreading electronic wave packets and conductance fluctuations”, Phys. Rev. Lett. |

29. | D. Delande, J. Zakrzewski, and A. Buchleitner, “A wave packet can be a stationary state”, Europhys. Lett. |

30. | D. Farrelly, E. Lee, and T. Uzer, “Magnetic field stabilization of Rydberg wavepackets in a circulary polarized microwave field”, Phys. Lett. A |

31. | E. Lee, A. F. Brunello, and D. Farrelly, “A single atom Quasi-Penning trap”, Phys. Rev. Lett. |

32. | A. F. Brunello, D. Farrelly, and T. Uzer, “Nonstationary, nondispersive wave packets in a Rydberg atom”, Phys. Rev. Lett. |

33. | E. Lee, A. F. Brunello, and D. Farrelly, “Coherent states in a Rydberg atom: Classical mechanics”, Phys. Rev. A |

34. | C. Cerjan, E. Lee, D. Farrelly, and T. Uzer, “Coherent states in a Rydberg atom: Quantum mechanics”, Phys. Rev. A |

35. | K. Hornberger and A. Buchleitner, “Spontaneous decay of nondispersive wave packets”, (to be published). |

36. | Z. Bialynicki-Birula and I. Bialynicki-Birula, “Radiative decay of Trojan wave packets”, (to be published). |

37. | G. W. Hill, Am. J. Math. |

38. | R. Greenberg and D. R. Davis, “Stability at potential maxima: The L |

39. | Deprit, in The Big Bang and George Lemaitre, edt. A. Berger, (Reidel, Dordrecht, 1984), pp. 151–180. |

**OCIS Codes**

(020.0020) Atomic and molecular physics : Atomic and molecular physics

(020.5780) Atomic and molecular physics : Rydberg states

**ToC Category:**

Focus Issue: Rydberg wave packets

**History**

Original Manuscript: August 22, 1997

Published: September 29, 1997

**Citation**

Ernestine Lee, David Farrelly, and Turgay Uzer, "A Saturnian atom," Opt. Express **1**, 221-228 (1997)

http://www.opticsinfobase.org/oe/abstract.cfm?URI=oe-1-7-221

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### References

- E. Rutherford, Phil. Mag. 21, 669 (1911). [CrossRef]
- E. Nagaoka, "Kinetics of a system of particles illustrating the line and the band spectrum and the phenomena of radioactivity", Phil. Mag. 7, 445-455 (1904). [CrossRef]
- N. Bohr, Phil. Mag. 26, 1-25 (1913); ibid., 476-502; ibid., 857-875. [CrossRef]
- M. Born, The Mechanics of the Atom, (republished by F. Ungar, New York, 1960) (translated by J.W. Fisher); pp. 130-241.
- G. Raithel, M. Fauth, H. Walther, " Atoms in strong crossed electric and magnetic fields: Evidence for states with large electric-dipole moments", Phys. Rev. A 47 , 419-440 (1991). [CrossRef]
- H. Dehmelt, "Nobel Prize Lecture", Rev. Mod. Phys. 62, 525-531 (1992). [CrossRef]
- J. A. Burns, L. Schaer, "Orbital evolution of circumplanetary dust by resonant charge variations", Nature 337, 340-343 (1989). [CrossRef]
- L. Schaer, L. and Burns, "Charged dust in planetary magnetospheres: Hamiltonian dynamics and numerical simulations for highly charged grains", J. Geophys. Res. 99, 17211-17223 (1994). [CrossRef]
- T. F. Gallagher, Rydberg Atoms, (Cambridge University Press, Cambridge, 1994). [CrossRef]
- M. Nauenberg, "Quantum wave packets on Kepler elliptic orbits", Phys. Rev. A 40, 1133-1136 (1989). [CrossRef] [PubMed]
- A. O. Barut, B. W. Xu, " Non-spreading coherent states riding on Kepler orbits", Helv. Phys. Act. 66, 712-720 (1993).
- J. A. Yeazell, C. R. Stroud, "Observation of fractional revivals in the evolution of a Rydberg atomic wave packet", Phys. Rev. A 43, 5153-5156 (1991). [CrossRef] [PubMed]
- P. Fu, T. J. Scholz, J. M. Hettema, T. F. Gallagher, "Ionization of Rydberg atoms by circularly polarized microwave field", Phys. Rev. Lett. 64, 511-514 (1990). [CrossRef] [PubMed]
- C. H. Cheng, C. Y. Lee, T. F. Gallagher, "Production of circular Rydberg states with circularly polarized microwave fields", Phys. Rev. Lett. 73, 3078-3081 (1994). [CrossRef] [PubMed]
- M. Nauenberg, Comment on "Ionization of Rydberg states by a circularly polarized microwave field", Phys. Rev. Lett. 64, 2731 (1990). [CrossRef] [PubMed]
- M. Nauenberg, "Canonical Kepler map", Europhys. Lett. 13, 611-616 (1990). [CrossRef]
- P. Kappertz, M. Nauenberg, "Circularly polarized microwave ionization of hydrogen", Phys. Rev. A 47, 4749-4755 (1993). [CrossRef] [PubMed]
- V. Szebehely, Theory of orbits: The restricted problem of three bodies, (Academic, New York and London, 1967).
- D. Farrelly and T. Uzer, "Ionization mechanism of Rydberg atoms in a circulary polarized microwave field",Phys. Rev. Lett. 74, 1720-1723 (1995). [CrossRef] [PubMed]
- I. Bialynicki-Birula, M. Kalinski, J. H. Eberly, "Lagrange equilibrium points in celestial mechanics and nonspreading wave packets for strongly driven Rydberg electrons", Phys. Rev. Lett. 73, 1777-1780 (1994). [CrossRef] [PubMed]
- M. Kalinski, J. H. Eberly, I. Bialynicki-Birula,"Numerical observation of stable field supported Rydberg wave packets", Phys. Rev. A 52, 2460-2463 (1995). [CrossRef]
- M. Kalinski, J. H. Eberly, "Trojan wave packets: Mathieu theory and generation from circular states", Phys. Rev. A 53, 1715-1724 (1996). [CrossRef]
- M. Kalinski, J. H. Eberly,"New states of hydrogen in a circulary polarized microwave field", Phys. Rev. Lett. 77, 2420-2423 (1995). [CrossRef]
- D. Farrelly, E. Lee, T. Uzer, Comment on "Lagrange equilibrium points in celestial mechanics and nonspreading wave packets for strongly driven Rydberg electrons", Phys. Rev. Lett. 75, 972 (1995). [CrossRef] [PubMed]
- I. Bialynicki-Birula, M. Kalinski, J. H. Eberly, Reply to Ref. 22, Phys. Rev. Lett. 75, 973 (1995). [CrossRef] [PubMed]
- A. Buchleitner, These de doctorat, Universite Pierre et Marie Currie, Paris, 1993 (unpublished).
- A. Buchleitner, D. Delande, "Nondispersive electronic wave packets in multiphoton processes", Phys. Rev. Lett. 75, 1487-1490 (1995). [CrossRef] [PubMed]
- J. Zakrzewski, D. Delande, A. Buchleitner, "Nonspreading electronic wave packets and conductance uctuations", Phys. Rev. Lett. 75, 4015-4018 (1995). [CrossRef] [PubMed]
- D. Delande, J. Zakrzewski, A. Buchleitner, " A wave packet can be a stationary state", Europhys. Lett. 32, 107-112 (1995). [CrossRef]
- D. Farrelly, E. Lee, T. Uzer, "Magnetic field stabilization of Rydberg wavepackets in a circulary polarized microwave field", Phys. Lett. A 204, 359-372 (1995). [CrossRef]
- E. Lee, A. F. Brunello, D. Farrelly, "A single atom Quasi-Penning trap", Phys. Rev. Lett. 75, 3641-3644 (1995). [CrossRef] [PubMed]
- A. F. Brunello, D. Farrelly, T. Uzer, "Nonstationary, nondispersive wave packets in a Rydberg atom", Phys. Rev. Lett. 76, 2874-2877 (1996). [CrossRef] [PubMed]
- E. Lee, A. F. Brunello, D. Farrelly, "Coherent states in a Rydberg atom: Classical mechanics", Phys. Rev. A 55, 2203-2221 (1997). [CrossRef]
- C. Cerjan, E. Lee, D. Farrelly, T. Uzer, "Coherent states in a Rydberg atom: Quantum mechanics", Phys. Rev. A 55, 2222-2231 (1997). [CrossRef]
- K. Hornberger, A. Buchleitner, "Spontaneous decay of nondispersive wave packets", (to be published).
- Z. Bialynicki-Birula, I. Bialynicki-Birula, "Radiative decay of Trojan wave packets", (to be published).
- G. W. Hill, Am. J. Math.1, 5-128, (1878). [CrossRef]
- R. Greenberg, D. R. Davis, "Stability at potential maxima: The L4 and L5 points of the Restricted Three-Body Problem", Am. J. Phys.46, 1068-1070, (1978). [CrossRef]
- A. Deprit, in The Big Bang and George Lemaitre, edt. A. Berger, (Reidel, Dordrecht, 1984), pp. 151-180.

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