We show that polar molecules (water, ammonia, and nitrogen dioxide) adsorbed solely at the exposed edges of an encapsulated graphene sheet exhibit ferroelectricity, collectively orienting and switching reproducibly between two available states in response to an external electric field. This ferroelectric molecular switching introduces drastic modifications to the graphene bulk conductivity and produces a large and ambipolar charge bistability in micrometer-size graphene devices. This system comprises an experimental realization of envisioned memory capacitive (“memcapacitive”) devices whose capacitance is a function of their charging history, here conceived via confined and correlated polar molecules at the one-dimensional edge of a two-dimensional crystal.

中文翻译：

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石墨烯边缘铁电分子开关

我们表明，仅吸附在封装的石墨烯片的裸露边缘上的极性分子（水，氨和二氧化氮）显示出铁电性，响应于外部电场，共同定向和可复制地在两个可用状态之间切换。这种铁电分子转换极大地改变了石墨烯的体积电导率，并在微米级的石墨烯器件中产生了很大的双极性电荷双稳态性。该系统包括预想的存储电容（“ memcapacitive”）设备的实验实现，其电容是其充电历史的函数，此处的充电是通过二维晶体的一维边缘处的受约束和相关的极性分子构想的。