Ferroelectrics subject to suitable electric boundary conditions present a steady negative capacitance response^1,2. When the ferroelectric is in a heterostructure, this behaviour yields a voltage amplification in the other elements, which experience a potential difference larger than the one applied, holding promise for low-power electronics³. So far research has focused on verifying this effect and little is known about how to optimize it. Here, we describe an electrostatic theory of ferroelectric/dielectric superlattices, convenient model systems^4,5, and show the relationship between the negative permittivity of the ferroelectric layers and the voltage amplification in the dielectric ones. Then, we run simulations of PbTiO₃/SrTiO₃ superlattices to reveal the factors most strongly affecting the amplification. In particular, we find that giant effects (up to tenfold increases) can be obtained when PbTiO₃ is brought close to the so-called ‘incipient ferroelectric’ state.

铁电体受到合适的电边界条件呈现稳定的负电容响应^1,2。当铁电体处于异质结构时，这种行为会在其他元素中产生电压放大，这些元素的电势差大于所施加的电势差，有望用于低功率电子设备³。到目前为止，研究主要集中在验证这种效果，而对如何优化它知之甚少。在这里，我们描述了铁电/电介质超晶格的静电理论，方便的模型系统^4,5，并展示了铁电层的负介电常数与电介质层中的电压放大之间的关系。然后，我们运行 PbTiO ₃ /SrTiO的模拟_{3 个}超晶格揭示了对放大影响最强烈的因素。_{特别是，我们发现当 PbTiO 3}接近所谓的“初始铁电”状态时可以获得巨大的效果（增加十倍） 。