Arguing over picometers sounds like pure academic hair-splitting. It is not. The lack of a firm atomic edge creates concrete engineering hurdles for the semiconductor industry.
As commercial fabrication nodes push down toward 2-nanometer and sub-nanometer scales, the distance between transistor gates spans only a dozen atoms across. At these dimensions, electron probability clouds spill over physical barriers. Quantum tunneling occurs precisely because an electron wave function does not drop to zero at the edge of a silicon channel. Current leaks through gates, producing heat and logic errors.
Engineers cannot design modern microprocessors by treating atoms as rigid building blocks. Device models require full quantum mechanical calculations of electron density gradients to predict exactly where charge carriers will leak. The elusive boundary of the atom dictates the physical limits of modern computing.
