High-quality Resonator 4.3.4.4. For adiabatic reversible computing technologies operating at room temperature, the logic signal energy (e.g., 1⁄2CV2 in CMOS) remains a concern, since it still exists even in adiabatic circuits, and is merely transferred dynamically to the power- clock generator system, rather than being dissipated locally within the logic. Thus, to achieve significant overall energy savings at the system level, compared to the corresponding irreversible technology, this generator must be designed to efficiently recover a large fraction of this signal energy, e.g., by comprising a resonant oscillator with a high quality factor (Q). Designing extremely high-Q resonators and clock distribution networks already demands advanced, high-precision engineering. Further, as RF designers know, achieving high Q implies narrow bandwidth. This in turn implies that the *returned clock waveform must be extremely pristine*—e.g., any data-dependent back-action from the logic must be avoided. Thus, we must maintain a careful load balancing discipline, e.g., via complementary signaling. And if bulk semiconductors are used, this adds another level of challenges relating to time-varying loads during transitions, since device capacitances are more voltage-dependent when depletion regions are not structurally constrained. Thus, fully depleted SOI, thin-film, or gate- all-around (GAA) nanosheet/nanowire FET geometries may be preferred.