In this talk I will discuss the workings of the NIST timescale which generates UTC(NIST). Additionally, in support of the timescale, our group is also developing a singly-trapped 88Sr+ ion based clock. While the S1/2 -> D5/2 transition in the 88Sr+ ion system can support high precision, our initial goals of uncertainty at below a part in 1016 are comparatively modest. Our primary objective is rather high operational uptime in pursuit of frequent comparison with atomic clocks within the ensemble that forms the timescale. These frequent measurements will allow measurement and correction of the frequency drifts and random-walk of phase in the timescale with a lower noise floor and faster feedback than is possible with current two-way time transfer techniques. The strontium ion is an excellent candidate for a robust frequency standard as lasers at the necessary wavelengths (within 400-1200 nm) are all mature technologies and a single ion system with a “magic” trap RF drive frequency can enable low systematic uncertainty without significant experimental overhead. Comparison with the NIST-F4 cesium fountain enables absolute frequency measurements of the optical transition.
Speaker Bio:
Alejandra is a staff scientist in the Time Realization and Distribution group. She works on the timescale (an ensemble of atomic clocks) that generates the NIST realization of UTC, yielding the official US timing signals. Additionally, she works on developing an atomic optical frequency reference based on singly trapped strontium ions. This frequency reference aims to support the timescale as a high uptime optical standard for frequency calibration. Her education includes a B.S in physics from Stanford University and Ph.D. work at JILA (University of Colorado Boulder) under Professor Jun Ye implementing a magneto optical trap of diatomic YO molecules (2018). During her postdoctoral years she worked at NIST as an NRC research associate and later as a term employee in the Ion Storage group on experiments involving quantum logic spectroscopy, both for precision molecular spectroscopy and towards high-fidelity gates for scalable quantum computing (2018-2023).