Recent highlights

RECENT HIGHLIGHTS

Jahn-Teller states mixed by spin-orbit coupling in an electromagnetic field

Alejandro S. Miñarro, Gervasi Herranz

Phys. Rev. B 106, 165108 – (2022) https://doi.org/10.1103/PhysRevB.106.165108

Electrical characterization and extraction of activation energies of the defect states in the LaAlO₃/SrTiO₃ heterostructure

Yoann Lechaux, Yu Chen, Albert Minj, Florencio Sánchez, Gervasi Herranz, Laurence Méchin, and Bruno Guillet

https://doi.org/10.1063/5.0101255

Dynamic control of octahedral rotation in perovskites by defect engineering

Jiahui Jia, Xu He, Arsalan Akhtar, Gervasi Herranz, and Miguel Pruneda

Phys. Rev. B 105, 224112 – (2022)

A schematic of the proposed mechanism to control octahedral tilts. Small red circles represent the anions at the corners of the octahedra with the B cation in the center (blue circle).

Photoinduced Persistent Electron Accumulation and Depletion in LaAlO3/SrTiO3 Quantum Wells

Yu Chen, Yoann Lechaux, Blai Casals, Bruno Guillet, Albert Minj, Jaume Gázquez, Laurence Méchin, and Gervasi Herranz Phys. Rev. Lett. 124, 246804 (2020) https://doi.org/10.1103/PhysRevLett.124.246804

Persistent photoconductance is a phenomenon found in many semiconductors, by which light induces long-lived excitations in electronic states. Commonly, persistent photoexcitation leads to an increase of carriers (accumulation), though occasionally it can be negative (depletion). Here, we present the quantum well at the LaAlO3/SrTiO3 interface, where in addition to photoinduced accumulation, a secondary photoexcitation enables carrier depletion. The balance between both processes is wavelength dependent, and allows tunable accumulation or depletion in an asymmetric manner, depending on the relative arrival time of photons of different frequencies. We use Green’s function formalism to describe this unconventional photoexcitation, which paves the way to an optical implementation of neurobiologically inspired spike-timing-dependent plasticity.

Gap suppression at a Lifshitz transition in a multi-condensate superconductor

We have participated in this work, with a collaboration with Nicolas Bergeal (ESPCI-Paris-CNRS). Check our work, recently published in Nature Materials (https://doi.org/10.1038/s41563-019-0354-z).

For a brief summary of this research, please, read this note.

Fig. 1