Our group operates an ensemble of atomic clocks – a timescale - that generates the time signal UTC(NIST): the civil US realization of coordinated universal time (UTC). We widely distribute this time signal to provide synchronization for financial exchange, millions of Internet-connected devices, and radio-controlled clocks via NIST's radio transmissions without reliance on Global Navigation Satellite Systems (GNSS) like GPS. The timescale is based on microwave technologies, but ultra-stable lasers and optical atomic frequency references can now outperform their microwave counterparts by two orders of magnitude in stability and accuracy. Leveraging these modern optical technologies will lead to improved performance of the time scale, but doing so requires reliable designs with high operational duty-cycles.  Main project areas within our group are:

1:  Increasing robustness and continually modernizing aspects of the current timescale and time transfer methods [1].

2:  Incorporating data from optical clocks and frequency references into UTC(NIST) as well as increasing contribution of such optical frequency standards to time scales operated by the BIPM. These clocks could include a strontium ion optical clock operating within our group as well as those from other optical clock groups at NIST.

3: Maintaining and improving the cesium fountain clocks [2] that are NIST’s primary frequency standards, and which are a critical component in performing absolute frequency measurements of optical transitions in support of the redefinition of the second [3].

[1]  https://nvlpubs.nist.gov/nistpubs/TechnicalNotes/NIST.TN.2187.pdf

[2] V. Gerginov et al 2025 Metrologia 62 035002

[3]  N Dimarcq et al 2024 Metrologia 61 012001

atomic clock; atomic physics; timescale; laser spectroscopy; atomic spectroscopy; time; time distribution; quantum metrology; optical frequency standard; optical clock

citizenship

Open to U.S. citizens

level

Open to Postdoctoral applicants