Possible routes to superconductivity in the surface layers of V-doped Mg$_{1-δ}$Ti$_2$O$_4$ through multiple charge transfers and suppression of Jahn-Teller activity

Dibyendu Dey; T. Maitra; A. Taraphder

doi:10.1103/PhysRevB.107.174515

paper

Possible routes to superconductivity in the surface layers of V-doped Mg $_{1 - δ}$ Ti $_{2}$ O $_{4}$ through multiple charge transfers and suppression of Jahn-Teller activity

arXiv:2212.06245 · doi:10.1103/PhysRevB.107.174515

Abstract

Superconductivity in the family of spinel oxides is very rare owing to their robust Mott-insulating nature. About half a century ago, LiTi $_{2}$ O $_{4}$ became the first reported spinel compound to show superconductivity with a 12K transition temperature. Since then, several unsuccessful attempts were made to enhance the T $_{c}$ of this family of materials. However, a very recent experiment [arXiv:2209.02053] has reported superconductivity at a higher temperature (below 16K), in the V-doped Mg $_{1 - δ}$ Ti $_{2}$ O $_{4}$ thin surface layer while its bulk counterpart remains Mott insulating. The superconducting T $_{c}$ of this material is significantly higher compared to other engineered MgTi $_{2}$ O $_{4}$ thin films grown on different substrates. From our first-principles analysis, we have identified that Mg-depletion significantly reduces Jahn-Teller (JT) activity and antiferromagnetic superexchange at the surface layer of V-doped MgTi $_{2}$ O $_{4}$ due to considerable charge transfer between various ions. The combined effect of a degraded antiferromagnetic order and reduced JT activity weakens the Mottness of the system, leading to the emergence of superconductivity at higher temperatures.

Maine article - 12 pages (single column), 4 figures. Supplemental attached

Possible routes to superconductivity in the surface layers of V-doped Mg $_{1 - δ}$ Ti $_{2}$ O $_{4}$ through multiple charge transfers and suppression of Jahn-Teller activity

Abstract

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Possible routes to superconductivity in the surface layers of V-doped Mg1−δ​Ti2​O4​ through multiple charge transfers and suppression of Jahn-Teller activity

Abstract

References in corpus (10)

Cited by in corpus (2)

Possible routes to superconductivity in the surface layers of V-doped Mg $_{1 - δ}$ Ti $_{2}$ O $_{4}$ through multiple charge transfers and suppression of Jahn-Teller activity