Table 1 Fractional frequency gradients and corresponding uncertainties

From: A lab-based test of the gravitational redshift with a miniature clock network

Sources

Gradient

Uncertainty

 

( × 10−19/cm)

( × 10−19/cm)

BBRa

−15.7

1.5

Lattice light

−11.8

1.2

Densityb

–

1.0

2nd order Zeemana

−95.3

1.0

Probe Stark

0

0.5

DC Stark

0

0.1

Ellipse fittingb

–

0.5

Total systematic correction

+122.8

2.5

Statistical gradient

−135.2

0.7

Corrected gradient

−12.4

2.6

Expected redshift gradient

−10.9

<0.1

  1. Uncertainties are quoted as 1σ standard deviations. For each systematic effect, more discussion can be found in Supplementary Note 3.
  2. aThe BBR shift and second-order Zeeman shift are corrected for each measurement, here the weighted averaged values across all 14 measurements are listed
  3. bThe density shift and bias error from ellipse fitting are corrected for each pairwise clock comparison individually, and do not depend linearly on spatial separation.
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