The TIP experiment
current grad student: Nithiwadee Thaicharoen
former grad student: Andrew Schwarzkopf
Photo of tip and surrounding electrodes. The tip/needle (visible through the electrode window) is the key component of the imaging system, and gives the experiment its name. The electrodes give us electric field control in the sample volume.
We would like to study spatial structures in cold gases.
Specifically, we laser-cool 85Rb in a MOT (magneto-optic trap) and then excite some portion of those atoms to Rydberg states. There should be spatial correlations between the excited Rydberg atoms due to the "dipole blockade" effect. (See the Dipole Blockade project webpage, and the "Details" section below, for more details on this effect.)
The imaging system we have set up to study the dipole blockade effect could be used to study other spatial structures as well. For example, we could also look at:
- structures in expanding cold plasmas
- excitation-hopping / diffusion in Rydberg systems
- Rydberg crystals
2013: We have a paper:
A. Schwarzkopf, D. A. Anderson, N. Thaicharoen, and G. Raithel, "Spatial correlations between Rydberg atoms in an optical dipole trap," Phys. Rev. A 88, 061406(R) (2013)
2011: We have a paper:
A. Schwarzkopf, R. E. Sapiro, and G. Raithel, "Imaging Spatial Correlations of Rydberg Excitations in Cold Atom Clouds," PRL 107, no. 10 (2011): 103001.
2012: We are now working to get higher magnification in the setup, to see smaller structures. We might see Coulomb effects between ions (upon ionization of the Rydberg atoms) and perhaps Rydberg crystals.
A reasonable introduction to the experiment can be found on our 2010 DAMOP poster. (DAMOP is "Division of Atomic Molecular and Optical Physics", our yearly division conference.)
DAMOP posters from various years:
More detail about the scientific background of this experiment can be found in the writeup for my prelim examination. This document also includes references to the literature, and some more recent data.
- prelim writeup (1.7 MB)
A copy of my slides and notes for the presentation are below. The slides have more details on the references (figures, in particular).
A few previous graduate students in the Raithel lab designed and built the beginnings of the apparatus. My thanks to them for getting the project started. To my knowledge, here's what they did:
- designed & did calculations for the electrodes
- aquired essential equipment to construct experiment
- assembled electrodes and put them in the vacuum chamber
- set up vacuum chamber & initial optics