Professor Juan Bautista Roldán Aranda, from the Department of Electronics and computer technology at the University of Granada, welcomes postdoctoral candidates interested in applying for a Marie Skłodowska-Curie Individual Fellowships (MSCA-IF) in 2020 at this University. Please note that applicants must comply with the Mobility Rule (more information: http://sl.ugr.es/0aNV).

Brief description of the institution:

The University of Granada (UGR), founded in 1531, is one of the largest and most important universities in Spain. The UGR has been awarded with the "Human Resources Excellence in Research (HRS4R)", which reflects the UGR’s commitment to continuously improve its human resource policies in line with the European Charter for Researchers and the Code of Conduct for the Recruitment of Researchers. The UGR is also a leading institution in research, located in the top 5/10 of Spanish universities by a variety of ranking criteria, such as national R&D projects, fellowships awarded, publications, or international funding.

UGR is one of the few Spanish Universities listed in the Shanghai Top 500 ranking (http://sl.ugr.es/0aw0). The Academic Ranking of World Universities (ARWU) places the UGR in 268th position in the world and as the 4th highest ranked University in Spain, reaffirming its position as an institution at the forefront of national and international research. From the perspective of specialist areas in the ARWU rankings, the UGR is outstanding in Documentation (ranked in the 36th in the world) or Food science technology (ranked 37th in the world), Mathematics and Computer Science (ranked among the top 76-100 in the world).

The UGR has 4 researchers at the top of the Highly Cited Researchers (HCR) list in the Computer Science area. With regard to broader subject fields, the UGR is ranked in 45th position in the universities worldwide in the discipline of Engineering. It is also well recognized for its web presence (http://sl.ugr.es/0a6i) taking 36th place in the top 200 Universities in Europe. Internationally, we bet decidedly by our participation in the calls of the Framework Programme of the European Union. For the duration of the last two Framework Programmes, the UGR has obtained a total of 66 projects, with total funding of 18.02 million euros, and for H2020, 80 projects with total funding around 20.6 million euros.

Brief description of the Centre/Research Group

The members of our research group belong the following departments at the University of Granada: Electronics and computer technology, Atomic, molecular and nuclear physics, Applied mathematics and Optics. Therefore, we deal with research activities from a multidisciplinary viewpoint since our areas of expertise are complementary and allow to obtain many synergies. Among our research topics, the following can be counted: physical simulation and compact modeling for circuit simulation of electron devices, electron device experimental characterization, theoretical study of quantum phase transitions, analysis and study of two dimensional materials (graphene, silicene…) and topological insulators.

We have developed compact models for resistive memories, memristors, vision CMOS sensors, magnetic sensors based on giant magnetoresistances and different flavors of MOSFET devices, such as DGMOSFETs, gate-all-around devices, etc. For parameter extraction activities we have employed measurements obtain in our lab and in our collaborator’s. The compact models have been implemented with different techniques: Verilog AMS, Verilog-A, SPICE macromodels.

For the electron device simulation we have employed numerical methods based on Monte Carlo and drift-diffusion procedures including many types of 2D and 3D numerical grids, materials, and geometries. In doing this, we have being funded in research projects by the Spanish Ministry of Science and Universities, the Junta de Andalucía regional government and the European Union authorities.

Project description

We will develop a detailed and physically-based physical simulator for the study of different types of resistive memories. The simulation tool will be based on finite element description of a 3D domain where the electric potential, the temperature, the charge and ionic current will be obtained self-consistently to describe the device resistive switching processes. The simulation tool will be employed to fit great number of experimental data from different devices fabricated by our partners. In particular, we will consider devices based on metal-insulator-metal and metal-insulator-semiconductor made of different transition metal oxides stacks. In addition, we will take into consideration resistive memories where two-dimensional materials are included.

The simulation results will be used to describe the operation of these devices in applications for non-volatile circuits. The 3D microscopic simulations will be compared with previous tools developed in our group for these devices based on the kinetic Monte Carlo algorithm that include the redox reaction kinetic, the ion dynamics and the solution of the Poisson and heat equations within the device.

Some of our simulation tools are explained in videos for scientific visualization:

• https://www.youtube.com/watch?v=G0YacFensM4
• https://www.youtube.com/watch?v=OLk4eJNc_Y8
• https://www.youtube.com/watch?v=VoFF0svim6c&t=10s

We will address charge transport and the formation/rupture of conductive filaments that allow resistive switching in Conductive-Bridge RAMs, Valence Change Memories and other type of devices. Once the simulation tools is ready different analysis will be performed to deepen on the physics underlying resistive switching. Among other effects the following will be taken into account: thermal response, RTN, variability, etc. In addition, new numerical procedures will be contemplated to extract parameters from experimental data that will help to understand resistive memories physics.

Compact modeling will be also tackled using some of our models and new ones that will be developed.

This activities will be also included in topics related to neuromorphic circuits and implementation of neural networks at hardware level. The role of memristors based on resistive switching to mimic biological synapses will be addressed.

Research Area

Information Science and Engineering (ENG), Physics (PHY) and Mathematics (MAT)

For a correct evaluation of your candidature, please send the documents below to Professor Juan Bautista Roldán Aranda (jroldan@ugr.es):

• CV
• Letter of recommendation (optional)