Negative and positive magnetoresistance in the itinerant antiferromagnet BaMn2Pn2 ( Pn = P, As, Sb, and Bi)
| Autor: | Masayuki Hagiwara, Denis Arčon, Takanori Kida, Takuma Ogasawara, Time Tahara, Yoichi Tanabe, Keita Kitahara, Kim Khuong Huynh, Katsumi Tanigaki, Stephane Yu Matsushita |
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| Rok vydání: | 2019 |
| Předmět: |
Physics
Condensed matter physics Magnetoresistance Orbital hybridisation 02 engineering and technology 021001 nanoscience & nanotechnology Coupling (probability) 01 natural sciences Magnetic field Electrical resistivity and conductivity 0103 physical sciences Antiferromagnetism Condensed Matter::Strongly Correlated Electrons 010306 general physics 0210 nano-technology Anisotropy |
| Zdroj: | Physical Review B. 99 |
| ISSN: | 2469-9969 2469-9950 |
| Popis: | We report the discovery of a large-magnetoresistance (LMR) phenomenon in a family of ${\mathrm{BaMn}}_{2}{Pn}_{2}$ antiferromagnets ($Pn$ = P, As, Sb, and Bi) with parity-time symmetry. The resistivities of these materials are reduced by 60 times in magnetic fields $\mathbf{H}$, thus yielding a LMR of about $\ensuremath{-}98%$. The LMR changes systematically along with the $Pn$ elements, hinting that its origin is the spin-orbit coupling and/or $d\ensuremath{-}p$ orbital hybridization. A positive MR component emerging on top of the negative LMR at low temperatures suggests an orbital-sensitive magnetotransport as $\mathbf{H}$ suppresses the conduction of the electronlike carriers in the $d$-like band but enhances that of holelike ones in the $d\ensuremath{-}p$ hybridized band. The anisotropy of the LMR reveals that the electrical conductivity is extremely sensitive to the minute changes in the direction of the antiferromagnetic moments induced by the parity-time symmetry-breaking $\mathbf{H}$, which is perpendicular to the antiferromagnetic spin-ordered direction. We attribute the observed LMR to the nontrivial low-energy bands of ${\mathrm{BaMn}}_{2}{Pn}_{2}$ antiferromagnets, which are governed by the parity-time symmetry. |
| Databáze: | OpenAIRE |
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