2017/08/09 by Ravid Shaniv, Tom Manovitz, Yotam Shapira +2
Computer Science · Physics and Astronomy · #Atomic and Subatomic Physics Research #Atomic physics #Coherent states #Hamiltonian (control theory) #Heisenberg limit #Physics #Quantum #Quantum Information and Cryptography #Quantum entanglement #Quantum mechanics #Quantum optics and atomic interactions #Spectroscopy #quant-ph
paper · pdf · doi:10.1103/physrevlett.120.243603
published as Phys. Rev. Lett. 120, 243603 (2018) · 18 pages: Main text - 12 pages, 5 figures, references - 2 pages, Supplemental Materials - 4 pages, 4 figures
arxiv created 2017/08/09 · openalex publication_date 2018/06/14 · arxiv updated 2018/06/20 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
The use of entangled states was shown to improve the fundamental limits of spectroscopy to beyond the standard-quantum limit. Here, rather than probing the free evolution of the phase of an entangled state with respect to a local oscillator, we probe the evolution of an initially separable two-atom register under an Ising spin Hamiltonian with a transverse field. The resulting correlated spin-rotation spectrum is twice as narrow as that of an uncorrelated rotation. We implement this ideally Heisenberg-limited Rabi spectroscopy scheme on the optical-clock electric-quadrupole transition of 88Sr+ using a two-ion crystal. We further show that depending on the initial state, correlated rotation can occur in two orthogonal subspaces of the full Hilbert space, yielding entanglement-enhanced spectroscopy of either the average transition frequency of the two ions or their difference from the mean frequency. The use of correlated spin rotations can potentially lead to new paths for clock stability improvement.