Recent highlights

RECENT HIGHLIGHTS

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

A New Critical Thickness at Polar Interfaces

key_image_JGazquezPRL
A new critical thickness at LAO/STO interfaces

Magneto-optical response of polarons

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Charge transfer in Ce-doped YIG

Charge transfer in Ce-doped YIG

Electrons in LaAlO3/SrTiO3 quantum wells: symmetry matters.

Electrons moving in 2D: symmetry matters