Scale-free ferroelectricity induced by flat phonon bands in HfO<sub>2</sub>

doi:10.1126/science.aba0067

GSTDTAP > 气候变化

DOI	10.1126/science.aba0067
	Scale-free ferroelectricity induced by flat phonon bands in HfO₂
	Hyun-Jae Lee; Minseong Lee; Kyoungjun Lee; Jinhyeong Jo; Hyemi Yang; Yungyeom Kim; Seung Chul Chae; Umesh Waghmare; Jun Hee Lee
	2020-09-11
发表期刊	Science
出版年	2020
英文摘要	Ferroelectric materials are attractive because they provide a way to change electrical resistance by using an electric field. Lee et al. used simulations to explain the persistence of ferroelectric behavior in very thin films of hafnium oxide (see the Perspective by Noheda and Íñiguez). The authors' calculations show that ferroelectric properties should be found in films below 1 nanometer thick. This makes the material very attractive for the next generation of random access memory. Science , this issue p. [1343][1]; see also p. [1300][2] Discovery of robust yet reversibly switchable electric dipoles at reduced dimensions is critical to the advancement of nanoelectronics devices. Energy bands flat in momentum space generate robust localized states that are activated independently of each other. We determined that flat bands exist and induce robust yet independently switchable dipoles that exhibit a distinct ferroelectricity in hafnium dioxide (HfO2). Flat polar phonon bands in HfO2 cause extreme localization of electric dipoles within its irreducible half-unit cell widths (~3 angstroms). Contrary to conventional ferroelectrics with spread dipoles, those intrinsically localized dipoles are stable against extrinsic effects such as domain walls, surface exposure, and even miniaturization down to the angstrom scale. Moreover, the subnanometer-scale dipoles are individually switchable without creating any domain-wall energy cost. This offers unexpected opportunities for ultimately dense unit cell–by–unit cell ferroelectric switching devices that are directly integrable into silicon technology. [1]: /lookup/doi/10.1126/science.aba0067 [2]: /lookup/doi/10.1126/science.abd1212
领域	气候变化 ; 资源环境
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文献类型	期刊论文
条目标识符	http://119.78.100.173/C666/handle/2XK7JSWQ/294094
专题	气候变化资源环境科学
推荐引用方式 GB/T 7714	Hyun-Jae Lee,Minseong Lee,Kyoungjun Lee,et al. Scale-free ferroelectricity induced by flat phonon bands in HfO₂[J]. Science,2020.
APA	Hyun-Jae Lee.,Minseong Lee.,Kyoungjun Lee.,Jinhyeong Jo.,Hyemi Yang.,...&Jun Hee Lee.(2020).Scale-free ferroelectricity induced by flat phonon bands in HfO₂.Science.
MLA	Hyun-Jae Lee,et al."Scale-free ferroelectricity induced by flat phonon bands in HfO₂".Science (2020).