The raw data underlying the figures is stored in the file data/eigenmode_info_data_frame.csv. In this notebook we explain what this file contains and the data format.
The data is stored in CSV (= comma-separated values) format. In principle, it is human-readable. The first few lines look as follows.
In [1]:
!head -n 5 ../data/eigenmode_info_data_frame.csv
However, it is much more convenient to read and explore the data using pandas. To do this, we first load the CSV file into a pandas.DataFrame.
In [2]:
import pandas as pd
In [3]:
df = pd.read_csv('../data/eigenmode_info_data_frame.csv')
Using pandas we can display the data in a nice table format. The first few entries of the data frame (which correspond to the lines listed above) look as follows.
In [4]:
df.head(4)
Out[4]:
Each row contains the simulation parameters and computed eigenfrequency for one of the five eigenmodes computed in a particular simulation run. The rows shown above all correspond to a simulation with no particle present, hence the missing values (marked by NaN = "not a number") for some of the parameters. For illustration, we also show a few rows corresponding to simulations which included a particle.
In [5]:
df.iloc[103:107]
Out[5]:
In each simulation run we computed the frequencies of the first five eigenmodes (N=1,...,5) of the nanodisc as illustrated in the following figures (cf. Figs. 3 and 5 in the paper). Each row in the data frame corresponds to one of these eigenmodes, either for the bare nanodisc (as illustrated on the left), or for a nanodisc with particle (as illustrated for selected modes on the right).
The meaning of the columns in the data frame is as follows:
has_particle: Whether a particle was present in this particular simulation. If False, the simulation computed eigenmodes of the bare disc.
x, y: Position of the centre of the particle relative to the centre of the nanodisc (in nanometres). The value (x,y)=(0,0) means that the particle is located above the centre of the disc.
d: Separation (in nanometres) of the bottom surface of the particle from the top surface of the disc. See Fig. 1(c) in the paper for illustration.
d_particle: Diameter of the particle (in nanometres).
Ms_particle: Saturation magnetisation of the particle (in A/m).
Hx, Hy, Hz: Strength of the external field (in A/m).
N: Which eigenmode of the nanodisc this row corresponds to. Valid values are N=1,...,5, corresponding to the first five eigenmodes of the disc. See figures above for illustration.
freq: Frequency of the eigenmode (in GHz).
freq_diff: Frequency shift $\Delta f$ (in GHz) of this eigenmode relative to the same mode in the bare disc (i.e., with no particle present).