  We report the detection of CO(6-5) and CO(7-6) and their underlying continua
from the host galaxy of quasar J100758.264+211529.207 (P\=oniu\=a'ena) at
z=7.5419, obtained with the NOrthern Extended Millimeter Array (NOEMA).
P\=oniu\=a'ena belongs to the HYPerluminous quasars at the Epoch of
ReionizatION (HYPERION) sample of 17 $z>6$ quasars selected to be powered by
supermassive black holes (SMBH) which experienced the fastest mass growth in
the first Gyr of the Universe. The one reported here is the highest-redshift
measurement of the cold and dense molecular gas to date. The host galaxy is
unresolved and the line luminosity implies a molecular reservoir of $\rm
M(H_2)=(2.2\pm0.2)\times 10^{10}$ $\rm M_\odot$, assuming a CO spectral line
energy distribution typical of high-redshift quasars and a conversion factor
$\alpha=0.8$ $\rm M_{\odot} (K\,km \, s^{-1} \,pc^{2})^{-1} $. We model the
cold dust spectral energy distribution (SED) to derive a dust mass of M$_{\rm
dust} =(2.1\pm 0.7)\times 10^8$ $\rm M_\odot$, and thus a gas to dust ratio
$\sim100$. Both the gas and dust mass are not dissimilar from the reservoir
found for luminous quasars at $z\sim6$. We use the CO detection to derive an
estimate of the cosmic mass density of $\rm H_2$, $\Omega_{H_2} \simeq 1.31
\times 10^{-5}$. This value is in line with the general trend suggested by
literature estimates at $ z < 7 $ and agrees fairly well with the latest
theoretical expectations of non-equilibrium molecular-chemistry cosmological
simulations of cold gas at early times.
