  We present a thorough analysis of the foundations of models of stabilization
of negative capacitance (NC) in a ferroelectric (FE) layer by capacitance
matching to a dielectric layer, which claim that the FE is stabilized in a low
polarization state without FE polarization switching (non-switching), showing
that the concept is fundamentally flawed and unphysical. We also analyze
experimental evidence concluding that there is no data supporting the need to
invoke such stabilization; rather, conventional models of ferroelectric
polarization switching suffice to account for the effects observed. We analyze
experimental evidence that at least in some of the model systems for which this
effect has been claimed, categorically rule out stabilized non-switching NC.
Microscopic measurements recently published as supporting non-switching
stabilized NC actually rule them out, since the ferroelectric in a stack
sandwiched between two dielectric layers was found to be in a mixed domain
state (high polarizations within each domain) rather than in the low
polarization state predicted by non-switching stabilized NC models.
Nonetheless, since stabilized NC (corresponding to a minimum in free energy) is
not physically impossible, it would be useful to move the research efforts to
investigating scenarios and systems in which this effect is possible and
expected and assess whether they are useful and practical for low power
electronics.
