Photo credit: Yale University
A team of researchers has demonstrated a single-molecule electret for the first time – a device that could be one of the keys to molecular computing.
Smaller electronics are critical to the development of more advanced computers and other devices. This has led to an effort in the field of finding a way to replace silicon chips with molecules. This includes creating a single-molecule electret – a switching device that could serve as a platform for extremely small non-volatile storage devices. Since it appeared that such a device would be so unstable, many in the field wondered if there could ever be one.
Harold Hodgkinson Professor of Electrical Engineering and Applied Physics, along with colleagues from Nanjing University, Renmin University, Xiamen University and Rensselaer Polytechnic Institute, Mark Reed, demonstrated a single-molecule electret with a functional memory. The results were published on October 12, 2020 in Nature nanotechnology.
Most electrets are made of piezoelectric materials, such as those used to make the sound in speakers. In an electret, all dipoles – pairs of opposing electrical charges – spontaneously align themselves in the same direction. Their directions can be reversed by applying an electric field.
“The question has always been how small you can make these electrets, which are essentially storage devices,” Reed said.
The researchers added atom of gadolinium (Gd) in a carbon buckyball, a 32-sided molecule also known as buckminster fullerene. If the researchers set this construct ([email protected]) in a transistor-type structure, they observed single-electron transport and used it to understand its energy states. The real breakthrough, however, was that they discovered that they could use an electric field to switch its energy state from one stable state to another.
“What happened is that this molecule acts as if it has two stable polarization states,” Reed said. He added that the team conducted various experiments in which the transport properties were measured while an electric field was applied and the states were switched back and forth. “We showed that we can remember it – read, write, read, write,” he said.
Reed emphasized that the present device structure is not currently feasible for any application, but proves that the underlying science behind it is possible.
“The most important thing is that you can create two states in a molecule that cause spontaneous polarization and two switchable states,” he said. “And this can give people ideas that maybe you can literally shrink your memory down to the single molecular level. Now that we understand we can, we can do other interesting things with it. ”
Reference: “A. [email protected]82 Single Molecule Electret “by Kangkang Zhang, Cong Wang, Minhao Zhang, Zhanbin Bai, Fang-Fang Xie, Yuan-Zhi Tan, Yilv Guo, Kuo-Juei Hu, Lu Cao, Shuai Zhang, Xuecou Tu, Danfeng Pan, Lin Kang, Jian Chen, Peiheng Wu, Xuefeng Wang, Jinlan Wang, Junming Liu, Du Lied, Guanghou Wang, Fengqi Lied, Wei Ji, Su-Yuan Xie, Su-Fei Shi, Mark A. Reed and Baigeng Wang, October 12, 2020, Nature nanotechnology.
DOI: 10.1038 / s41565-020-00778-z
