The Mechanism of Primordial Dark Energy Mass Generation Under the Nested Potential Difference Paradigm — A Fundamental Ultimate Traceability of the Square Term in the Mass-Energy Equation E=mc²

The mass-energy relation E=mc² of the special theory of relativity only completes the quantitative equivalent fitting of energy and mass and can accurately describe the law of mass-energy conversion, yet it has a major physical blind spot: modern physics cannot explain the dynamic cause why the mass-energy coupling coefficient equals the speed of light squared c² from the primordial level, nor define the critical condition for the transition from massless radiation field to massive physical particles. Based on the dual global framework of CLΛ positive primordial dark energy and ZWΛ negative primordial dark energy, this paper puts forward a physical model of nested potential difference: cosmic spacetime expansion forms the underlying Λ field via the first-order global potential difference of positive and negative primordial energies; photons and vacuum radiation exist inside the Λ field, and local ZWΛ doping produces a second-order embedded potential difference within the difference, and this linear potential difference corresponds to the benchmark cosmic light speed c. Research verifies that when the second-order embedded potential difference undergoes negative convergent polarization and jumps to the square energy level of (ΔΛ)², the binding force of negative primordial energy counteracts the spatial repulsive force of dark energy Λ, vacuum field energy gets locked and solidified, and static mass comes into being natively. This theory supplements the long-missing underlying mechanism of the c² square term in physics over the past century, unifies three core propositions including the origin of light speed, origin of mass and spacetime expansion, and establishes a self-consistent new paradigm for fundamental physics.