FRIB graduate research assistants Jacob Watkins and Erin White earn National Science Foundation graduate fellowships

19 June 2020

Michigan State University (MSU) students Jacob Watkins and Erin White have earned three-year fellowships from the National Science Foundation (NSF) Graduate Research Fellowship Program. Both Watkins and White are graduate research assistants at the Facility for Rare Isotope Beams (FRIB) Laboratory. NSF provides an annual stipend of $34,000 to each recipient, as well as up to $12,000 for tuition and fees.

Watkins’s research interests center around quantum computation and information, with special focus on algorithms for quantum simulation. He has also taken interest in open quantum systems and decoherence.

“Together with Professor Dean Lee, I have developed and characterized an algorithm for determining bound states of systems with localized interactions, known as projected cooling,” said Watkins. “The method hinges on the idea that any quantum state is in a superposition of energy states, some of which may be bound, some unbound. Only the bound states should remain in the interaction region after a long time passes, while others should disperse away. By waiting until the unbound states have left the starting region, we can ‘project’ them out, leaving us with only the bound state of interest.”

Watkins said one of the challenges is understanding how fast the unbound states disperse, and under what conditions. He would like to adapt the algorithm to run on a quantum computer, which for current or near-term hardware would likely require clever ideas for mitigating noise. If a quantum algorithm is viable, one of the first applications will likely be in nuclear physics, where bound states are often few and highly localized.

White is studying nuclear physics and astrophysics as a part of Spinlab, the research group of Jaideep Singh, MSU assistant professor of physics at FRIB. She is working on the Single Atom Microscope project, which sets out to measure certain rare nuclear reactions more precisely than any other current method. One key to understanding where the chemical elements come from lies within the nuclear reactions occurring in stars. Finding a precise way to measure these reactions would provide insight into the life cycles of stars and the elements’ origins.

“In order to measure nuclear reactions more precisely, our chosen method is to capture everything, all of the product atoms and the unreacted beam, in a cryogenically frozen solid,” said White. “Then the product atoms can be counted with single atom sensitivity through the utilization of optical fluorescence. This proposed method could provide better efficiency, selectivity, and sensitivity than any other method.”

To advance this method, White said she will show that they can detect with single-atom sensitivity. Using the prototype single atom microscope, or pSAM, an intense beam incident on a dense target would scatter product atoms in the general direction of a noble gas solid that is cryogenically frozen onto a substrate. All of the product atoms and unreacted beam atoms would be captured in this solid allowing for efficient detection of product atoms. After capture, a laser excites the product atoms to fluoresce light which a charge-coupled device camera collects. Due to the unique absorption and emission wavelengths of the product, optical filters can distinguish between them to select the wavelength range of interest.

White has developed a technique for growing optically transparent 100 micron noble gas films, studied the time-dependent optical transparency of these films as a function of temperature, and wrote procedures to document the method of growing films and conducting annealing tests.