Adam V. Steele

My Company

zeroK NanoTech Corporation

I co-founded zeroK with Brenton Knuffman to develop the next generation of focused ion beam systems and Secondary Ion Mass Spectrometry (SIMS) elemental analysis equipment. As of 2020 zeroK is delivering these systems to customers. You can learn more at

Scientific Research and Education

Advanced Ion Sources

Since 2009 I have worked to develop new ion sources that will improve the performance of focused ion beam Instruments. These sources work by first laser-cooling and then photoionizing an atomic vapor. Using these techniques ion sources of chromium, lithium, and cesium have been created. The latest cesium source is very high-performing and is now being developed as one of the first commercial applications of laser-cooling.

Since 2013 this work has been done with my colleagues at zeroK NanoTech. From 2009-2012 this research was done at NIST as part of my post-doctoral fellowship with the group of Jabez McClelland.

Tin spheres on a carbon substrate. The field of view is 10 µm. To generate this picture the focused beam is rastered across the surface. In each pixel the beam sits for about 16 µs, during which so-called secondary electrons generated by the impact of the ion beam are collected and interpreted as a grey level.

This image was taken using the zeroK LoTIS Cs+ FIB prototype.

Laser Cooling

The common thread in all of my research is the use of lasers to bring an atoms from room temperature or above down to a as low as a few millionths of a degree of absolute zero. Laser-cooling was critical to the creation of the ion sources described above, and can be applied to reduce the temperature of both neutral atoms and ions.

Learn more at Wikipedia.

Ion and Atom Trapping

Longer term confinement is usually needed in order to achieve and make use of the ultra-cold temperatures enabled by the laser cooling. In the context of this section, long-term means timescales longer than those required for a uncooled particle to pass through the lasers.

In the video above you can see a few dozen 138Ba+ ions fluoresce under the influence of laser light. Each dot of light here really is a single atom! The video is real-time, and the field of view left-to-right is about a millimeter if I recall correctly. They are confined in a radio frequency ion trap. The crystaline structure they collectively exhibit owes the fact that they have been brought to very cold temperatures by the laser-cooling process. They occasionally shift position when the crystal is disturbed by a collision with a background gas molecule. You may also note two positions in the crystal where ions appear to be 'missing'. There are ions here, but since they are of a different isotope (likely 137Ba) they do not fluoresce at the same laser frequencies as does the 138Ba+. The structure is one that minimizes the energy of the overall arrangement, this is often called a Wigner (or Coulomb) crystal.



I hold a PhD from Georgia Institute of Technology and a B.S in physics and computer science from Carnegie-Mellon University.