Over the recent years, we have investigated the properties of quantum wells (QWs) at the LaAlO3/SrTiO3 interface, including 2D superconductivity, Rashba spin-orbit fields and lattice vibrational modes [see References 1-3 below]. More recently we have uncovered persistent photoconductance (PPC), whereby the system changes its conductance in a plastic way, retaining memory from its past history, as in the case of memristors, but using light instead of electric pulses. Our most recent discovery  is that light pulses can be used to replicate spike timing-dependent plasticity (STDP). STDP was proposed to emulate time causality of electro-chemical signals in biological neurons: pre-synaptic neurons spiking after post-synaptic neurons are “anti-causal” and learning is weakened; pre-synaptic neurons spiking before post-synaptic neurons are causal, reinforcing learning. STDP enables unsupervised learning, without need of labelling training data.
Our discovery is particularly relevant, as it extends the STDP concept beyond electrical stimuli to the realm optical stimuli, opening up whole new perspectives on neuromorphic engineering and in artificial vision. We develop algorithms that will help to understand how artificial networks can be designed to learn from visual inputs, with the ultimate objective of building a first design that may learn from simple visual patterns.
 Pesquera et al., Physical Review Letters 2014. https://doi.org/10.1103/PhysRevLett.113.156802
 Herranz et al., Nature Communications 2015. https://doi.org/10.1038/ncomms7028
 Gazquez et al., Physical Review Letters 2017. https://doi.org/10.1103/PhysRevLett.119.106102
 Y. Chen et al., submitted.