Atomic mirror explained

In physics, an atomic mirror is a device which reflects neutral atoms in a way similar to the way a conventional mirror reflects visible light. Atomic mirrors can be made of electric fields or magnetic fields,^[1] electromagnetic waves^[2] or just silicon wafer; in the last case, atoms are reflected by the attracting tails of the van der Waals attraction (see quantum reflection).^{[3] [4] [5]} Such reflection is efficient when the normal component of the wavenumber of the atoms is small or comparable to the effective depth of the attraction potential (roughly, the distance at which the potential becomes comparable to the kinetic energy of the atom). To reduce the normal component, most atomic mirrors are blazed at the grazing incidence.

At grazing incidence, the efficiency of the quantum reflection can be enhanced by a surface covered with ridges (ridged mirror).^{[6] [7] [8] [9]}

The set of narrow ridges reduces the van der Waals attraction of atoms to the surfaces and enhances the reflection. Each ridge blocks part of the wavefront, causing Fresnel diffraction.^[8]

Such a mirror can be interpreted in terms of the Zeno effect.^[7] We may assume that the atom is "absorbed" or "measured" at the ridges. Frequent measuring (narrowly spaced ridges) suppresses the transition of the particle to the half-space with absorbers, causing specular reflection. At large separation

~L~ between thin ridges, the reflectivity of the ridged mirror is determined by dimensionless momentum ~p = \sqrt{KL~}~\theta~ , and does not depend on the origin of the wave; therefore, it is suitable for reflection of atoms.

Applications

• Atomic interferometry

See also

• Quantum reflection
• Ridged mirror
• Zeno effect
• Atomic nanoscope
• Atom laser

Notes and References

1. H. Merimeche. Atomic beam focusing with a curved magnetic mirror. Journal of Physics B. 39 . 18 . 3723–3731. 2006. 10.1088/0953-4075/39/18/002. 2006JPhB...39.3723M . 121851648.
2. V. I. Balykin. V. S. Letokhov . Yu. B. Ovchinnikov . A. I. Sidorov. . amp. Quantum-State-Selective Mirror Reflection of Atoms by Laser Light.. Physical Review Letters. 60 . 21 . 2137–2140. 1988. 10.1103/PhysRevLett.60.2137. 1988PhRvL..60.2137B . 10038269.
3. H. Friedrich. G. Jacoby, C. G. Meister. quantum reflection by Casimir–van der Waals potential tails. 2002. Physical Review A. 65 . 3 . 032902 . 10.1103/PhysRevA.65.032902. 2002PhRvA..65c2902F .
4. F. Shimizu. 34195829. 2001. Specular Reflection of Very Slow Metastable Neon Atoms from a Solid Surface. Physical Review Letters. 86 . 6 . 987–990. 10.1103/PhysRevLett.86.987. 2001PhRvL..86..987S . 11177991.
5. H. Oberst. Y. Tashiro . K. Shimizu . F. Shimizu. 2005. Quantum reflection of He* on silicon. Physical Review A. 71 . 5 . 052901. 10.1103/PhysRevA.71.052901. 2005PhRvA..71e2901O .
6. F. Shimizu. J. Fujita. 2002. Giant Quantum Reflection of Neon Atoms from a Ridged Silicon Surface. Journal of the Physical Society of Japan. 71 . 1. 5–8. 10.1143/JPSJ.71.5. physics/0111115 . 2002JPSJ...71....5S . 19013515.
7. D. Kouznetsov. H. Oberst. 2005. Reflection of Waves from a Ridged Surface and the Zeno Effect. Optical Review. 12 . 5 . 1605–1623. 10.1007/s10043-005-0363-9. 2005OptRv..12..363K. 55565166.
8. H. Oberst. D. Kouznetsov . K. Shimizu . J. Fujita . F. Shimizu. 2005. Fresnel Diffraction Mirror for an Atomic Wave. Physical Review Letters. 94 . 1 . 013203 . 10.1103/PhysRevLett.94.013203. 2005PhRvL..94a3203O . 15698079. 2241/104208. free.
9. D. Kouznetsov . H. Oberst . 2005 . Scattering of waves at ridged mirrors. . . 72 . 1 . 013617 . 10.1103/PhysRevA.72.013617 . 2005PhRvA..72a3617K .