Strong-correlation induced high-mobility electrons in Dirac semimetal of perovskite oxide

Abstract

Electrons in conventional metals become less mobile under the influence of electron correlation. Contrary to this empirical knowledge, we report here that electrons with the highest mobility ever found in known bulk oxide semiconductors emerge in the strong-correlation regime of the Dirac semimetal of perovskite CaIrO3. The transport measurements reveal that the high mobility exceeding 60,000 cm2V−1s−1 originates from the proximity of the Fermi energy to the Dirac node (ΔE < 10 meV). The calculation based on the density functional theory and the dynamical mean field theory reveals that the energy difference becomes smaller as the system approaches the Mott transition, highlighting a crucial role of correlation effects cooperating with the spin-orbit coupling. The correlation-induced self-tuning of Dirac node enables the quantum limit at a modest magnetic field with a giant magnetoresistance, thus providing an ideal platform to study the novel phenomena of correlated Dirac electron.

Charge Density Waves and Magnetism in Topological Semimetal Candidates GdSbxTe2−x−δ

“…For example, topological antiferromagnetic spintronics have recently been proposed to be realizable with antiferromagnetic TSMs . Besides the signature feature of nontrivial band topology, adding strong correlations to a TSM can give rise to new topological states and phenomena that cannot exist in a noninteracting system . However, the number of discovered correlated TSMs so far is even smaller .…”

Ground-state atlas of a three-dimensional semimetal in the quantum limit

“…When the magnetic field is tilted from the z-axis to Zaxis with Z ≡ −x sin θ+z cos θ (0 ≥ θ < π), the excitonic pairing in the bulk remains intact; the three-dimensional semimetal model has a spatially isotropic effective mass [Eqs. (4,5)]. Meanwhile, the (2 + 1)D massless surface Dirac fermion on the side surface (yz plane) forms Landau levels due to a finite out-of-surface component of the magnetic field.…”

“…Specifically, we add in Eqs. (5,6) a confining potential V c (X) that depends only on X ≡ x cos θ + z sin θ. For simplicity, we take the system is translationally symmetric along the y-direction, so that −i ∂ y in Eqs.…”

“…For simplicity, we take the system is translationally symmetric along the y-direction, so that −i ∂ y in Eqs. (5,6) is replaced by k y . This gives out…”

“…One of the fundamental challenge in condensed matter physics is a realization of three-dimensional unconventional electronic phases in the quantum limit 1 . Recent experimental discoveries of Dirac, Weyl and nodal Dirac semimetal materials 2 lead to growing research interests on novel quantum transports and quantum phase transitions under high magnetic field in these new compounds [3][4][5]7,25 as well as celebrated semimetal compounds such as bismuth 8,16 and graphite [11][12][13][14] . In fact, these semimetallic compounds under the high field often exhibit low-temperature metal-insulator transitions within wide ranges of the field 3,5,10-17 .…”