Fields Without Forces

Akira Tonomura, Franco Nori

Xianfeng Chen, Fang Jian-Xing, Zhu Shi-Qun

In this paper, the light pressure force in low and high intensity laser fields is derived. The exact numerical results of forces F n ∥(n=0,1,2,3,4,5,6...) through the matrix continued fraction method are presented. At low intensity field (G=1), the spatially averaged force F 0 ∥ gives a cooling effect at the negative detuning. At high intensity (G=64), the effects of the forces with higher order (n≥2) appear and the contributes of the forces with odd or even order are opposite. It is great different from no high order force at low intensity.

V. I. Balykin, Vladilen S Letokhov

Depending on the spatial and temporal structure of light field, its strength and wavelength, the radiation force may be a very complex function of the atoms position and velocity. But, since all the known studies on the application of the radiation forces have been carried out mainly using three types of light fields, namely, a plane traveling light field, a Gaussian laser beam and a standing light wave, or their combination, this chapter restricts to qualitative consideration of these types of fields only. At low radiation intensity and for a two level atom the radiation force in the standing wave is determined by the sum of the forces from each traveling waves. In the presence of static magnetic field the radiative forces acting on a multilevel atom in a laser field may acquire new properties. Of particular interest for the creation of new types of atomic traps is a confining potential — like character of the radiation force.

James G. Glimm, Arthur M. Jaffe

A. P. Kazantsev, Lev Davidovič Landau, I. V. Krasnov

A radiation-pressure force, changing only slightly within the wavelength of light (rectification effect), has been shown to arise in interfering fields. In a monochromatic field a rectified force (RF) has the scale of a spontaneous light-pressure force, and it is mainly a vortex one. In a bichromatic field the RF has the order of magnitude of the induced light-pressure force and does saturate in a strong field. The spatial RF structure can be either potential or rotational. The depth of the potential wells generated by the RF can exceed by several orders of magnitude the energy of the atom–field interaction, and it can reach 10 K and larger. A vortex periodic RF results either in regular rotating motion or in a random walk of atoms along the boundaries of elementary cells of the force field. Possible applications of the RF are discussed.

Daniel F. Walls, Gerard J Milburn