  The generalized parton distributions (GPDs) offer a window on
three-dimensional imaging of the nucleon, providing understanding of how the
fundamental properties of the nucleon, such as its mass and spin, arise from
the underlying quark and gluon degrees of freedom. In this work, we present the
first lattice calculation of the nucleon isovector helicity GPD at physical
pion mass, using an $a \approx 0.09$ fm lattice ensemble with 2+1+1 flavors of
highly improved staggered quarks generated by MILC Collaboration. We perform
the GPD calculation in Breit frame using averaged nucleon boost momentum $P_z
\approx 2.2$ GeV with nonzero momentum transfers in $[0.2,1.0]\text{ GeV}^2$.
Nonperturbative renormalization in RI/MOM scheme is used to obtain the
quasi-distribution before matching to the lightcone GPDs. The three-dimensional
distribution $\tilde{H}(x,Q^2)$ is presented, along with the three-dimensional
nucleon tomography and impact-parameter--dependent distribution for selected
Bjorken $x$ at $\mu=3$ GeV in $\overline{\text{MS}}$ scheme.
