Goals achieved   Demonstration of electrostatic force on Rydberg atoms.  Deflection of Lithium atomic beam.  High numbers of atoms in specific Rydberg and Stark State.
Coherent excitation to Rydberg state - STIRAP.  Focusing of Helium atomic beam with hexapole lens.

        Atom optics has become subject of intense investigation in recent years. Control of atomic motion is of the great importance atomic physics and applications like lithography or nanofabrication. 

         Neutral atoms are not affected greatly by magnetic or electric field as they don't have a charge or large magnetic and electric moments. But by exciting a neutral atom to a high Rydberg state it is possible to increase its electric moment considerably. The purpose of this work is to demonstrate experimentally and theoretically the possibility of creating atom optical elements for the beam of neutral atoms based on the polarizability of highly excited states in an electric field. It provides the background for the next logical step in atom optics, namely, the manipulation of neutral atoms using an electric field. Although the original idea was first introduced in 1981, it took rather long time to develop the proper experimental techniques to realize it.

      Following our first successful demonstration of electrostatic forces on Rydberg atoms in Lithium, experimental investigations were switched to Helium. The two-step excitation that was used allowed considerable increase of the population of the Rydberg state. Excitation to the energy levels with higher principal quantum numbers having longer the higher lifetime led to the increase of the effective interaction length. Several experimental improvements reduced the linewidth of the Rydberg resonance by factor of 20 compared to the Lithium atomic beam. This might allow more accurate spectroscopic measurements. In addition, coherent excitation to the Rydberg state using STIRAP was first demonstrated. Large numbers of atoms in specific Rydberg and Stark states were observed. And, finally, the focusing of beam neutral atoms was realized. 

       Our technique could be applied to any neutral atom as any neutral atoms that can be put into Rydberg states. Those atoms then can be used in a "direct deposition mode" or in a "lithography mode" Using atoms that have a metastable state such as Helium, is especially important for the "lithography mode". When such atoms are incident on the surface they have enough energy to destroy bonds in the polymeric molecules of self-assembling monolayers (SAMs), which could then removed from the substrate for later processing. Although these experiments are the first ones in the field, there is a great interest in this experimental technique and more improvements and new discoveries are certainly imminent.

Publications:

O. Kritsun, O. Boiko, and Harold Metcalf. Focusing Rydberg Atoms in an Inhomogeneous DC Electric Field, Bull. Am. Phys. Soc. 49, 28 (2004)

O. Kritsun, O. Boiko, and Harold Metcalf. Excitation of Metastable Helium Atoms to Rydberg States by STIRAP, Bull. Am. Phys. Soc. 49, 29 (2004)

O. Kritsun, O. Boiko, and Harold Metcalf. Atom Optics with Rydberg States in Inhomogeneous Electric fields. Intern. Workshop and Seminar Rydberg Physics (2004), Dresden, Germany.

O. Kritsun, B. Dietzik, and H. Metcalf. Producing Rydberg States of Helium Using STIRAP, Bull. Am. Phys. Soc. 47, 109 (2002)

O. Kritsun and H. Metcalf. Atom Optics with Rydberg States in Inhomogeneous Electric Fields, Proc. ICAP 2002

O. Kritsun, F. Tudorica, and H. Metcalf. Manipulation of Rydberg Atoms in Inhomogeneous Electric Fields, Bull. Am. Phys. Soc. 45, 110 (2000).

O. Kritsun, F. Tudorica, and H. Metcalf. Manipulation of Rydberg Atoms in Inhomogeneous Electric Fields. Proceedings of Trapp. Part. and Fund. Phys. Session (2000), Les Houches, France.

O. Kritsun, J. Marburger, and H. Metcalf. Interference From A Source of Atoms Released in a Gravitational Field, Bull. Am. Phys. Soc. 43, 1366 (1998).

"Coherent Excitation of Lithium to Rydberg States and Application to Atom Optics", (G. Stevens, M. Widmer, F. Tudorica, C.-H. Iu, and H. Metcalf), Bull. Am. Phys. Soc. 41, 1121 (1996) FP21.

"Deflection Schemes Using Rydberg Atom Mirror", with F. Tudorica, O. Kritsun, G. Stevens, and H. Metcalf), Bull. Am. Phys. Soc. 43 (1998).

T. Breeden and H. Metcalf, Phys. Rev. Lett. 47, 1726 (1981).