arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 1804.05487cond-mat.mtrl-scicond-mat.str-el
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室温下的人工二维极性金属

Artificial two-dimensional polar metal at room temperature

Yanwei Cao, Zhen Wang, Se Young Park, Yakun Yuan, Xiaoran Liu, Sergey M. Nikitin, Hirofumi Akamatsu, M. Kareev, S. Middey, D. Meyers, P. Thompson, P. J. Ryan, P… 展开作者

Yanwei Cao, Zhen Wang, Se Young Park, Yakun Yuan, Xiaoran Liu, Sergey M. Nikitin, Hirofumi Akamatsu, M. Kareev, S. Middey, D. Meyers, P. Thompson, P. J. Ryan, Padraic Shafer, A. N'Diaye, E. Arenholz, Venkatraman Gopalan, Yimei Zhu, Karin M. Rabe, J. Chakhalain

摘要:

通常由极性晶体结构和金属性共存定义的极性金属被认为是稀缺的,因为期望有利于极性结构的长程静电场被金属的传导电子完全屏蔽。此外,从三维减少到二维,极性金属是否存在仍然是一个悬而未决的问题。本文报道了在三色(三层)超晶格BaTiO $_3$ /SrTiO $_3$ /LaTiO $_3$中实现B位型的室温二维极性金属。结合原子分辨率扫描透射电子显微镜与电子能量损失谱,光学二次谐波产生,电输运,和第一性原理计算揭示了周期性电极化的强度,电荷分布和轨道对称性的微观机制。我们的研究结果提供了一条路线,创造全氧化物人工非中心对称准二维金属与异国情调的量子态,包括共存的铁电,铁磁和超导相。

英文摘要:

Polar metals, commonly defined by the coexistence of polar crystal structure and metallicity, are thought to be scarce because the long-range electrostatic fields favoring the polar structure are expected to be fully screened by the conduction electrons of a metal. Moreover, reducing from three to two dimensions, it remains an open question whether a polar metal can exist. Here we report on the realization of a room temperature two-dimensional polar metal of the B-site type in tri-color (tri-layer) superlattices BaTiO$_3$/SrTiO$_3$/LaTiO$_3$. A combination of atomic resolution scanning transmission electron microscopy with electron energy loss spectroscopy, optical second harmonic generation, electrical transport, and first-principles calculations have revealed the microscopic mechanisms of periodic electric polarization, charge distribution, and orbital symmetry. Our results provide a route to creating all-oxide artificial non-centrosymmetric quasi-two-dimensional metals with exotic quantum states including coexisting ferroelectric, ferromagnetic, and superconducting phases.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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