Direct measurement of ferroelectric polarization in a tunable semimetal
| Autor: | Vineetha S. Bheemarasetty, Wenguang Zhu, Di Xiao, Sergio C. de la Barrera, David Mandrus, Jiaqiang Yan, Yang Gao, Benjamin Hunt, Yuan Gao, Qingrui Cao |
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| Jazyk: | angličtina |
| Rok vydání: | 2021 |
| Předmět: |
Ferroelectrics and multiferroics
Materials science Science General Physics and Astronomy FOS: Physical sciences Two-dimensional materials Characterization and analytical techniques General Biochemistry Genetics and Molecular Biology Article Condensed Matter::Materials Science Electrical resistance and conductance Electric field Mesoscale and Nanoscale Physics (cond-mat.mes-hall) Polarization (electrochemistry) Mesoscopic physics Condensed Matter - Materials Science Multidisciplinary Condensed matter physics Condensed Matter - Mesoscale and Nanoscale Physics Materials Science (cond-mat.mtrl-sci) General Chemistry Ferroelectricity Semimetal Electric dipole moment Ferromagnetism Condensed Matter::Strongly Correlated Electrons |
| Zdroj: | Nature Communications Nature Communications, Vol 12, Iss 1, Pp 1-9 (2021) |
| ISSN: | 2041-1723 |
| Popis: | Ferroelectricity, the electrostatic counterpart to ferromagnetism, has long been thought to be incompatible with metallicity due to screening of electric dipoles and external electric fields by itinerant charges. Recent measurements, however, demonstrated signatures of ferroelectric switching in the electrical conductance of bilayers and trilayers of WTe2, a semimetallic transition metal dichalcogenide with broken inversion symmetry. An especially promising aspect of this system is that the density of electrons and holes can be continuously tuned by an external gate voltage. This degree of freedom enables measurement of the spontaneous polarization as free carriers are added to the system. Here we employ capacitive sensing in dual-gated mesoscopic devices of bilayer WTe2 to directly measure the spontaneous polarization in the metallic state and quantify the effect of free carriers on the polarization in the conduction and valence bands, separately. We compare our results to a low-energy model for the electronic bands and identify the layer-polarized states that contribute to transport and polarization simultaneously. Bilayer WTe2 is thus shown to be a fully tunable ferroelectric metal and an ideal platform for exploring polar ordering, ferroelectric transitions, and applications in the presence of free carriers. Free carriers and electrical polarization coexist in ferroelectric metals. Here, the authors use a capacitive method to probe the electronic compressibility of free carriers in a tunable semimetal, extract the polarized contribution, and study the carrier dependence of the ferroelectric state. |
| Databáze: | OpenAIRE |
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