Frequency measurement of the 1 S 0 , F = 5 / 2 ↔ 3 P 1 , F = 7 / 2 transition of ²⁷Al⁺ via quantum logic spectroscopy with ⁴⁰Ca⁺

Abstract

Keywords: trapped ions, mixed ion crystals, quantum logic spectroscopy, frequency standard, metrology P , 7 2 3 1 = = 0.428 133(2).

Role of hyperfine interaction in Landé $g$-factors of $^3\!P^o_0$ clock states

“…Comparing this value with the DHF result, we found that the one-electron relativistic effect is 0.073% for the g( 3 P o 1 ) and 0.004% for the g( 1 P o 1 ). Guggemos et al measured the g-factor of hyperfine state 3s3p 3 P o 1 with F = 7/2 in the 27 Al + ion by the quantum logic spectroscopy, and reported two results: 0.42884(1) [25] and 0.428133(2) [26]. Note that the discrepancy between these two values exceeds the experimental error bars of both cases.…”

Lifetime-Limited Interrogation of Two Independent ${}^{27}\textrm{Al}^{+}$ Clocks Using Correlation Spectroscopy

“…Atom-laser decoherence (for example, due to laser frequency fluctuations or atomic spontaneous emission) alters this picture by reducing the contrast of the Ramsey fringe by a factor C(T R ) < 1, which depends on the probe duration. In many optical clocks, including the 27 Al + clocks in this letter, decoherence over the relevant timescales is dominated by flicker-frequency noise of the laser [4]. This limits the probe duration that minimizes measurement instability, which has been evaluated analytically and through numerical simulation [5,6,11,12].…”

“…Both the 1 S 0 and 3 P 0 states in 27 Al + have a magnetic quantum number of F = 5/2. We performed initial correlation spectroscopy experiments on the 1 S 0 , m F = 5/2 ↔ 3 P 0 , m F = 5/2 transition, which has a sensitivity to magnetic fields of −4.2 kHz/G (1 G = 10 −4 T).…”

“…The frequencies of the sequentially applied laser pulses are tuned to be on resonance for each m F transition. Because the 3 P 1 , F = 7/2 manifold has g F ≈ 3/7 [22,27], the splitting of the transition frequencies for adjacent Zeeman levels is near 1 MHz at typical operating magnetic fields of 1.5 to 1.7 G, and these optical pumping transitions (pulse durations t π > 50 µs) are frequency-resolved. The target state is thus a dark state of the optical pumping process.…”

“…( 3). We attribute this primarily to errors in the 27 Al + state preparation and π-pulse infidelity when driving the clock transition.…”