Raw Data to 'Experimental verification of the area law of mutual information in quantum field theory', arXiv:2206.10563

Absorption images representing the raw data for arXiv:2206.10563

'scan5722.zip' contains the raw data for figures 2 and 3.

'scan5831.zip' and 'scan9617.zip' contain the raw data for figure 5, right and left, respectively.

All three datasets, 9617, 5722, and 5831, are used to obtain the data points in figure 4, from low to high temperatures.

Scans 5722 & 5831

The absorption images are numbered consecutively.

The first image for scans 5722 and 5831 is taken along the axial (longitudinal) direction with our 'longitudinal' imaging system after 10 ms time of flight (TOF) to measure the atom number balance between the two wells. The measurement is performed before ramping up the DW barrier. Two images are taken in each cycle: One shot with atoms ('1-atomcloud.tif') and a second image to record the intensity of the imaging beam without atoms ('1-withoutatoms.tif'). These two pictures are used to extract the atomic density (see the Matlab script).

The second image for scans 5722 and 5831 is taken in the direction of the double-well (DW) separation with our 'transverse' imaging system. The measurement is performed before ramping up the DW barrier. The image is taken after 11.2 ms TOF.

The subsequent images record the interference fringes for the different evolution times (again, always pairs '-atomcloud.tif' and '-withoutatoms.tif'). They are taken with our 'vertical' imaging system after 15.6 ms TOF. The imaging direction is perpendicular to the weakly confined direction of the clouds and the DW separation.

The recorded evolution times for scan 5722 are -1.9 ms (right before ramping up the DW barrier), 0 ms (right after the DW barrier is ramped up), and then in steps of 2.5 ms until 65 ms. This means that '3-atomcloud.tif' corresponds to -1.9 ms, and '30-atomcloud.tif' corresponds to 65 ms. This completes the 'first repeat'. The next two shots, '31-atomcloud.tif' and '32-atomcloud.tif', belong to the 'second repeat' and are again taken with the 'longitudinal' & 'transverse' imaging systems, respectively. The picture '33-atomcloud.tif' is again taken with the 'vertical' imaging and corresponds to -1.9 ms. And so forth.

In the same way, the pictures scan 5831 are ordered. The evolution times (in ms) for these two scans are:

scan 5722: -1.9 from 0 to 65 (in steps of 2.5)

scan 5831: -1.8, from 0 to 65 (in steps of 2.5)

The first time always corresponds to the instant right before the DW barrier is ramped up. 0 is always right after the barrier was ramped up.

Scan 9617

This scan only contains images with the 'vertical' imaging system with 15.6 ms TOF. The evolution times (in ms) are as follows:

scan 9617: -2.8, from 0 to 15 (in steps of 1.5),  22, 25, 28

The first time always corresponds to the instant right before the DW barrier is ramped up. 0 is always right after the barrier was ramped up.

This means, that '1-atomcloud.tif', '16-atomcloud.tif',  '31-atomcloud.tif' and so on correspond to -2.8 ms, and '15-atomcloud.tif', '30-atomcloud.tif', '45-atomcloud.tif' and so on correspond to 28 ms.

Matlab script

In addition to the data, a Matlab script (calc_atomic_density.m) illustrates how to extract the two-dimensional atomic density from the absorption images. It contains all relevant parameters of the imaging systems.