import matplotlib.pyplot as plt

kw = dict(
    usetex=True,
    fontsize=40,
    bbox=dict(boxstyle='round,pad=0', fc='lightsteelblue', ec='none')
)

plt.axhline(y=0.7)
plt.annotate('A', xy=(0.3, 0.7), **kw)
plt.annotate(r'$A$', xy=(0.4, 0.7), **kw)
plt.annotate(r'$^{\tiny 1}A$', xy=(0.5, 0.7), **kw)
plt.annotate(r'$^{\tiny 1j}A$', xy=(0.65, 0.7), **kw)

plt.axhline(y=0.4)
plt.annotate('A', xy=(0.3, 0.4), va='bottom', **kw)
plt.annotate(r'$A$', xy=(0.4, 0.4), va='bottom', **kw)
plt.annotate(r'$^{1}A$', xy=(0.5, 0.4), va='bottom', **kw)
plt.annotate(r'$^{1j}A$', xy=(0.65, 0.4), va='bottom', **kw)

plt.show()