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

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...

Descripción completa

Detalles Bibliográficos
Autores: Chen, Yu, Lechaux, Yoann, Casals, Blai, Guillet, Bruno, Minj, Albert, Gázquez, Jaume, Méchin, Laurence, Herranz, Gervasi
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2020
País:España
Institución:Consejo Superior de Investigaciones Científicas (CSIC)
Repositorio:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/220951
Acceso en línea:http://hdl.handle.net/10261/220951
Access Level:acceso abierto
Palabra clave:Potoconductivity
Photoinduced effect
Interfaces
Two-dimensional electron gas
Descripción
Sumario: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 LaAlO 3 / SrTiO 3 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.