2018/05/11 by Justin C. Wong, Wong, Justin C., Sayeef Salahuddin +1
Engineering · Materials Science · #Applied Physics (physics.app-ph) #FOS: Physical sciences #Ferroelectric and Negative Capacitance Devices #Ferroelectric and Piezoelectric Materials #Materials Science (cond-mat.mtrl-sci) #Multiferroics and related materials
paper · pdf · doi:10.48550/arxiv.1805.04259
openalex publication_date 2018/05/11 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Half of the energy is always lost when charging a capacitor. Even in the\nlimit of vanishing resistance, half of the charging energy is still lost--to\nradiation instead of heat. While this fraction can technically be reduced by\ncharging adiabatically, it otherwise places a fundamental limit on the charging\nefficiency of a capacitor. Here we show that this 1/2 limit can be broken by\ncoupling a ferroelectric to the capacitor dielectric. Maxwell's equations are\nsolved for the coupled system to analyze energy flow from the perspective of\nPoynting's theorem and show that (1) total energy dissipation is reduced below\nthe fundamental limit during charging and discharging; (2) energy is saved by\n"recycling" the energy already stored in the ferroelectric phase transition;\nand (3) this phase transition energy is directly transferred between the\nferroelectric and dielectric during charging and discharging. These results\ndemystify recent works on low energy negative capacitance devices as well as\nlay the foundation for improving fundamental energy efficiency in all devices\nthat rely on energy storage in electric fields.\n