We report an optical lattice clock with a total systematic uncertainty of 8.1 × 10−19 in fractional frequency units, representing the lowest uncertainty of any clock to date. The clock relies on interrogating the ultranarrow 1S0 → 3P0 transition in a dilute ensemble of fermionic strontium atoms trapped in a vertically-oriented, shallow, one-dimensional optical lattice. Using imaging spectroscopy, we previously demonstrated record high atomic coherence time and measurement precision enabled by precise control of collisional shifts and the lattice light shift. In this work, we revise the black body radiation shift correction by evaluating the 5s4d 3D1 lifetime, necessitating precise characterization and control of many body effects in the 5s4d 3D1 decay. Last, we measure the second order Zeeman coefficient on the least magnetically sensitive clock transition. All other systematic effects have uncertainties below 1 × 10−19.
BT - Physical Review Letters DA - 2024-07 DO - 10.1103/PhysRevLett.133.023401 N2 -We report an optical lattice clock with a total systematic uncertainty of 8.1 × 10−19 in fractional frequency units, representing the lowest uncertainty of any clock to date. The clock relies on interrogating the ultranarrow 1S0 → 3P0 transition in a dilute ensemble of fermionic strontium atoms trapped in a vertically-oriented, shallow, one-dimensional optical lattice. Using imaging spectroscopy, we previously demonstrated record high atomic coherence time and measurement precision enabled by precise control of collisional shifts and the lattice light shift. In this work, we revise the black body radiation shift correction by evaluating the 5s4d 3D1 lifetime, necessitating precise characterization and control of many body effects in the 5s4d 3D1 decay. Last, we measure the second order Zeeman coefficient on the least magnetically sensitive clock transition. All other systematic effects have uncertainties below 1 × 10−19.
PY - 2024 EP - 023401 T2 - Physical Review Letters TI - Clock with 8 × 10^{−19} Systematic Uncertainty UR - https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.133.023401 VL - 133 ER -