1. Artificial two-dimensional polar metal at room temperature.
- Author
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Cao, Yanwei, Wang, Zhen, Park, Se Young, Yuan, Yakun, Liu, Xiaoran, Nikitin, Sergey M, Akamatsu, Hirofumi, Kareev, M, Middey, S, Meyers, D, Thompson, P, Ryan, PJ, Shafer, Padraic, N'Diaye, A, Arenholz, E, Gopalan, Venkatraman, Zhu, Yimei, Rabe, Karin M, and Chakhalian, J more...
- Subjects
cond-mat.mtrl-sci ,cond-mat.str-el - Abstract
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 BaTiO3/SrTiO3/LaTiO3. 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. more...
- Published
- 2018