  Quantum chromodynamics (QCD) rigorously predicts the existence of both
nonperturbative intrinsic and perturbative extrinsic heavy quark contents of
nucleons. In this article we discuss the heavy quark electroproduction on
protons induced by the Fock states $|uud+g\rangle$ of three valence quarks in
the proton and a nonperturbative gluon, and the $|uud+Q\bar Q\rangle$
non-perturbative state of three valence quarks and a heavy quark-antiquark
pair. The first one gives the perturbative contribution when the gluon produces
a heavy quark pair, while the second is the intrinsic part, and they produce
amplitude interference. We use nonperturbative light-front wavefunctions for
these Fock states, which are computed using the color-confining light-front
holographic QCD theory. Due to interference of the amplitudes corresponding to
the intrinsic and extrinsic heavy quark contribution to the proton a novel $Q$
vs. $\bar Q$ asymmetry emerges in the differential cross section of the
electroproduction off a proton $d^2\sigma_{e^-p}/(dx dQ^2)$. Our analysis
proposed a novel asymmetry in QCD between intrinsic and extrinsic heavy quark
content in nucleon and provides new insights into the physics of heavy quark
phenomena in QCD at the amplitude level. This asymmetry is similar to the
Brodsky-Gillespie asymmetry discovered before in QED case and confirmed at
DESY.
