This Readme file was generated by Nicholas Bingham binghamn@gmail.com General Information 1. Title: Experimental realization of 1D Ising model 2. Author information Nicholas S Bingham Yale University Spencer Rooke University of Illinois at Urbana-Champaign, Urbana Jungsik Park University of Illinois at Urbana-Champaign, Urbana Alejandro Simon Yale University William Zhu Yale University Xiaoyu Zhang Yale University Joseph Batley University of Minnesota Justin D. Watts University of Minnesota Chris Leighton University of Minnesota, Karen A. Dahmen University of Illinois at Urbana-Champaign, Urbana Peter Schiffer Yale University 3. Description of data set Enclosed you will find all of the raw magnetic force microscopy (MFM) images as well as the digitized spin maps for the Experimental realization of the 1D random field Ising Model manuscript (DOI:10.1103/PhysRevLett.127.207203). In addition, the raw squid-VSM data from figure 1. We only show the virgin (0 Oe to 1000 Oe) curve in the manuscript, however the data for the entire loop is available. The field of view (FOV) for the raw MFM images are as follow: L (number of islands per side) = 70: FOV = 19 microns x 19 microns L = 80: FOV = 22 microns x 22 microns L = 100: FOV = 27 microns x 27 microns For the SI simulations folder, we are showing the generated spin maps for the nearest neighbor (NN) model, long range interactions, and Lorentzian distribution simulations which are presented in the supplemental information. All of the figures in the manuscript and supplemental information were produced from these images and data. 4. Abbreviations used L - the number of ferromagnetic islands per side of an array FOV - Field of view SI - supplemental information MFM - magnetic force microscopy NN - nearest neighbor 5. Folder information SI simulations - Long Range L=100 - these are simulated data while taking long-range magnetic interactions into consideration, the files are named as "N100H###" where N100 represents the L=100 array and H### is the simulated applied field value. Also included are the log-linear (perc1inc100) and log-log (percinc100) plots of the complementary cumulative distribution functions as a function of avalanche cluster size. Lorentzian L=70 - contains Lorentzian fits to the experimental data for the L = 70 array, the file names are "N70H###" where N70 represents the L=70 array and H### is the applied field value. Also included are the log-linear (perc1inc100) and log-log (percinc100) plots of the complementary cumulative distribution functions as a function of avalanche cluster size. Additionally, the probability of an avalanche growing as a function of applied magnetic field (H) in "normCDFinc70" Nearst Neighbor - NN L=70 - NN L=80- NN L=100- these are simulated data while taking only nearest neighbor magnetic interactions into consideration, the files are named as "N###H###" where N100 represents the L value for each array and H### is the simulated applied field value. Also included are the log-linear (perc1inc100) and log-log (percinc100) plots of the complementary cumulative distribution functions as a function of avalanche cluster size. Additionally, the probability of an avalanche growing as a function of applied magnetic field (H) in "normCDFinc###" where the ### here represents the L value. Spin Maps and raw MFM L = 70- Spin Maps and raw MFM L = 80- Spin Maps and raw MFM L = 100- These files contain raw MFM images and their corresponding digitized spin maps for the L=70,80, and 1000 arrays. Each folder contains four folders labeled "Bottom left, Bottom right, top left, and top right" indicating which array. We fabricated four, nominally identical arrays for each L. We did not use the Bottom Left array for L=80, or the Top Left array for L=100, as lithographic defects (such as missing islands) led to spurious results. These are labled with "didn't use in manuscript" Avalanche paper raw squid data - is the raw data collected from an MPMS3 (Quantum Design). The data shown in the manuscript (Figure 1 c), has the diamagnetic contribution from the background subtracted by fitting a linear slope to the data 800 < H < 1000 Oe and subtracting from the entire curve. Additionally, the data presented in the manuscript is normalized to the saturation magnetization at H=1000Oe.