CUA Seminar: David Hume – Quantum-limited measurements with the Al+ optical clocks at NIST

The Ion Storage Group at NIST has developed several generations of optical atomic clocks based on quantum logic spectroscopy of the ¹S₀–³P₀ transition in ²⁷Al⁺.  The latest version of this system began operation last year and achieves higher stability, longer continuous run times and lower systematic uncertainty than previous versions.  In this talk I will review the quantum-logic clock effort at NIST and introduce the newest system, which reaches an systematic uncertainty of 5.5×10^-19 and an instability averaging as 3.5×10^-16/(τ /s)^(1/2).  Further improvement to this instability could be achieved by using differential measurement techniques and by scaling the system to multiple clock ions, including the possibility of measurements with entangled states.