Creighton University, Department of Physics

Jonathan P. Wrubel, Ph.D. (Principal Investigator)

This is the research group page of the Laser-Cooled Atoms Group at Creighton University led by Dr. Jonathan Wrubel. Our group is building an experiment to probe quantum physics in a Bose-Einstein condensate of ⁴¹K (potassium-41).  This facinating state of matter is made by using lasers to cool gas atoms down to temperature below a millionth of a degree above absolute zero.  This novel state allows us to study quantum magnetism.

News

• October 2019: We have ultracold atoms! Below is an image of our 3D potassium magneto-optical trap (MOT). The gas of potassium atoms is held in ultrahigh vacuum by six counter-propagating laser beams. Next steps are to measure the temperature and number of the atoms in the MOT.
  
• March 2019: First placement of 3D MOT optics around science chamber. We need to back off to do some fine-tuning of the alignment, but we're getting close to a working 3D MOT.
  
• January 2019: The last AOM drivers have ben assembled and tested. The 3D MOT optics are 2/3 completed. Looking forward to a working 3D MOT in the next month.
• June 2018: We had five students attend the American Physical Society Annual Meeting of the Division of Atomic, Molecular, and Optical Physics (DAMOP) in Ft. Lauderdale, FL. M.S. Kellan Kremer (M.S., '19) and undergraduate Catie Ward (B.S., '18) presented posters. From left to right the group is (Gus Hernandez (B.S. '20), Matt Butschek II (M.S. '19), Catie Ward (B.S. '18), Matt Beauchem (B.S. '21), Kellan Kremer (M.S. '19), and Jonathan Wrubel (P.I.).
  
• May 2018: The quadrupole coils for the 3D MOT have been completed and tested!
  
• February 2018: Science chamber has been baked for 1.5 weeks at ~175˚C, and pumped down to 7.6x10^-11 Torr. This is 1 part in 10 trillion of atmospheric pressure! Imagine if every atom were the size of a ping-pong ball, then this is like filling Memorial Stadium in Lincoln to the top of the stadium with ping-pong balls 270 times over, and removing all but 1! (approximating the stadium as 180 m long x 130 m wide x 53 m deep)
  
• October 2017: Improved 2D MOT of potassium-39!
  
• July 2017: First 2D MOT of potassium-39! It needs to be optimized but it's great to have laser-cooled atoms! Next: a 2D MOT of potassium-41.
    
• July 2017: The glass octagonal science cell is installed and baking.
• April 2017: Catie's large square Helmholtz coils for controlling the experiment magnetic field are tested and working as predicted!
  
• March 2017: Research student Caitlyn Ward receives '17-'18 Clare Boothe Luce Scholarship! Congratulations Catie!
• August 2016: Rebuilt vacuum system achieved ultra-high vacuum.
• June 2016: Achieved 2G magnetic field in a resonant coil at 120 MHz!
• April 2016: Research student Alex Tarter receive a Barry Goldwater Scholarship! Congratulations Alex!
• March 2016: Research student Caitlyn Ward receives '16-'17 Clare Boothe Luce Scholarship! Congratulations Catie!
• August 2015: Alex finishes his improved and redisgned potassium oven.
• June 2015: Improved doppler-free absorption spectrum.
• May 2015: M.S. student Nathan Holman successfully defends his thesis: "Progress Towards A Spinor Bose-Einstein Condensate Machine". Nathan is going on to the Ph.D. program at UW Madison to study solid state quantum computing.
• March 2015: The tapered-amplifier is operational - achieving 1.6 W of light at 767 nm!
• February 2015: Dr. Wrubel receives a Cottrell College Science Award from the Research Corporation for Science Advancement! The title of the grant is: "Precision Measurement of a Microwave Fano-Feshbach Resonance in Ultracold ⁴¹K Atoms"
• January 2015: The ECDL is locked to the ³⁹K cross-over transition using a Doppler-free saturated absortpion technique.
  
• January 2014: The external cavity diode laser has its first light!  Nathan Holman (M.S. candidate) is getting it tuned to the correct wavelength.

Current group members

• Gustavo Hernandez (class of 2020) - 3D MOT coils
• W. Andy Peterson (M.S. candidate - 2017) - MOT/optical molasses hybrid simulations
• Joseph Preimesberger (class of 2018) - resonant RF field
• Caitlyn Ward (class of 2018) - active magnetic field stabilization

Past group members

• Alex Tarter (class of 2017) - K41 source, resonant RF field
• Sruti Prathivadhi-Bhayankaram (class of 2017) - michelson interferometer
• Shouvik Bhattacharya (M.S. candidate - 2016) - external field cancellation system
• Nathan Holman (M.S. candidate - 2015) - saturated absorption locking system
• Lucas Slattery (class of 2015) - source module
• Ben Schmachtenberger (class of 2015) - laser cavity construction
• Colin Bertsch (class of 2016) - vacuum equipment testing
• Steffen Lake (class of 2016) - laser cavity construction