  The subleading corner logarithmic corrections in entanglement entropy (EE)
are crucial for revealing universal characteristics of the quantum critical
points (QCPs), but they are challenging to detect. Motivated by recent
developments of stable computation of EE in (2+1)D quantum many body systems,
we develop a new method for directly measuring the corner contribution in EE
with less computational cost. The cornerstone of our approach is to measure the
subtracted corner entanglement entropy (SCEE) defined as the difference between
the EEs of subregions with the same boundary length for smooth and corner
entanglement boundaries in \textit{a single} quantum Monte Carlo simulation.
Our improved method inherently eliminates not only the area law term of EE but
also the subleading log-corrections arising from Goldstone modes, leaving the
universal corner contribution as the leading term of SCEE. Utilizing this
advanced approach, we calculate the SCEE of the bilayer Heisenberg model on
both square and honeycomb lattices across their (2+1)D O(3) QCPs with different
corner opening angles and obtain the accurate values of the corresponding
universal corner log-coefficients. These findings will encourage further
theoretical investigations in this field.
