READ ME This text describes the data presented in the paper: "Time-of-flight expansion of binary Bose¿Einstein condensates at finite temperatureÓ New J. Phys. (2018), arxiv:1712.07481 (http://iopscience.iop.org/article/10.1088/1367-2630/aaba39/meta) ======================== Introductory information ======================== Files included in the data deposit (within the compressed file raw_data.zip): 1) Density profiles in radial-azimuthal coordinates, stored in subfolder density_profiles 2) centers-of-mass of the condensates and thermal clouds of 87Rb and 39K as a function of time, stored in COM_vs_time. 3) centers-of-mass of the condensates and thermal clouds of 87Rb and 39K as a function of B field, stored in COM_vs_Bfield. Key words used to describe the data: time-of-flight, density profiles, center-of-mass. ========================== Methodological information ========================== A brief method description – what the data is, how and why it was collected or created, and how it was processed: The purpose of this data set is to investigate how the time-of-flight expansion of a two-component Bose-Einstein condensates has affected the experimental measurement on the miscible-immiscible transition. We compute the dynamical density profiles of the mixture for different temperatures, atom numbers and interaction strengths. Comparison of the column-integrated and doubly-integrated density profiles of the numerical data, as well as the shift in the center-of-mass of the different species demonstrates excellent agreement with the experimental data. This demonstrated the usefulness of the ZNG model to investigate dynamical expansion of condensates at finite temperature. Instruments, hardware and software used: Data is generated with ZNG model using code written by Kean Loon Lee (Newcastle University, email: leekeanloon@gmail.com). The code is written in Fortran, parallelised with OpenMP. Main data are collected on N8 clusters. During the testing and validation of codes, some simulations were also run on SAgE cluster (topsy). Details on the numerical implementation of the ZNG model can be found in the followings: 1) Appendices of this manuscript. 2) K. L. Lee and N. P. Proukakis, J. Phys. B: At. Mol. Opt. Phys. 49, 214003 (2016) 3) B. Jackson and E. Zaremba, Phys. Rev. A 66, 033606 (2002) 4) A. Griffin, T. Nikuni and E. Zaremba, "Bose-condensed Gases at Finite Temperatures", Cambridge University Press (2009) 5) A. J. Allen, PhD Thesis (Newcastle University, 2012), "Non-Equilibrium and Finite Temperature Trapped Bose Gases: Interactions and Decay of Macroscopic Excitations" Date(s) of data collection: June 2016 -- Feb 2017 Geographic coverage of data: na Data validation (how was the data checked, proofed and cleaned): Data from the two clusters have been cross-checked. For equilibrium profiles, we check the density profiles with those published in journal articles by other researchers. For ZNG simulations, we verify the correctness of our code by looking at other dynamical situations, e.g. Kohn mode, monopole oscillations, etc. that have been investigated and published by Jackson and Zaremba. Other conservation laws, such as conservation of momentum (as described in the manuscript), are also checked. Overview of secondary data, if used: na ========================= Data-specific information ========================= Definitions of names, labels, acronyms or specialist terminology uses for variables, records and their values: ÑÑÑÑÑÑÑÑÑ 1) folder density_profiles: there are two subfolders store data for the immiscible (delta=-0.93) and miscible (delta=1.2) case. Within each folder, the data are further categorized into different temperatures, where the subfolder names is of the form T{Rb temperature}_T{K temperature}. Within each temperature folder, there are density profiles [ n(rho,z) ] in binary format (written by Fortran program). The file name has the form {c/t}den{species}_t{time}.dat. For terms in the curly brackets, they carry the meaning c/t - condensate / thermal cloud species - 1:Rb, 2:K time - 0 : 0ms, 35000 : 14ms Do note that not all files are present in each folder. This is because, at a given temperature, a condensate / thermal cloud could be absent within the ZNG model. For example, no thermal clouds are found at zero temperature, hence no files with prefix ÕtÕ are found in the T0 folder. The fortran binary files can be read using the python function loadFortFile given at the end of this section. If you are using other plotting programs, such as Matlab, you will have to figure out the appropriate way to read the Fortran binary files. The binary first contains 2 real numbers (you can check quickly their values using file check.py provided in this depository), followed by 6000 (along radial) X 1500 (along z) real numbers. The 6000 X 1500 real numbers give the relevent density as number of atoms per reference unit^3. The reference unit (lref) is chosen to be 0.762165 micron. The radial position grids are given by the 6000 points, from rho=0.1*lref to rho= (0.1 + 5999*0.2)*lref The axial position grids are given by the 1500 points, from z= start_z*lref to (start_z+dz)*lref. The values of start_z and dz are the first two real numbers read from the fortran binaries files. At t=0ms, start_z = -299.6, dz= 0.4 for both condensate and thermal cloud. At t=14ms, start_z = -1198.4, dz=1.6 for thermal cloud, while those for condensate remains unchanged. ** python routine to read the Fortran binary files ** ################################ # load fortran binary file ################################ # raise the density to power and return it # (useful when we are reading wave function instead) # if fortran data file is complex, use c=true # else c = false def loadFortFile(path,n2,n1,lineskip,power,c): F = FortranFile(path,'r') for i in range(0,lineskip): temp = F.read_reals() pos_start = temp[0] dpos = temp[1] orig_den = F.read_reals() if(c): den=orig_den[::2].reshape((n2,n1)) else: den=orig_den.reshape((n2,n1)) return pos_start, dpos, np.power(den,power) ################################ **call it in the following way** st,cdz,cden1 = loadFortFile(path1,ny,nx,1,1,False) ÑÑÑÑÑÑÑÑÑ 2) folder COM_vs_time: center-of-mass () for immiscible (delta=-0.93) and miscible (delta=1.2) mixtures. length unit = 0.762165 micron time unit = 1./(2pi*200) seconds Meaning of each column: 1) 1st colum: time 2) 4th and 7th columns: of Rb and K condensates 3) 10th and 13th columns: of Rb and K thermal clouds 4) 16th and 19th columns: of Rb and K full clouds (i.e. condensate + thermal cloud) ÑÑÑÑÑÑÑÑÑ 3) folder COM_vs_Bfield: center-of-mass (COM) as a function of B field. To convert to the corresponding miscibility parameter, please use equations (1) and (2) of the manuscript to find the corresponding scattering lengths. The file name has the form: ComVsB_time{time}_sag{sag} For the term in curly brackets, time = time in ms sag = the separation of the trap-center of the two species. length unit = 0.762165 micron Meaning of each column: 1) 1st column: B field in Gauss 2) 4th and 7th column: of K condensates ÑÑÑÑÑÑÑÑÑ Explanation of weighting and grossing variables: na Outline any missing data: na ======= Contact ======= Please contact rdm@ncl.ac.uk for further information