Javier Junquera

Assistant Professor Universidad de Cantabria

Website

Biography

Javier Junquera got his BS. degree in physics at the Universidad de Oviedo (Spain) in 1996, and his PhD degree  from the Universidad Autónoma de Madrid in 2001. After a two years as postdoctoral fellow at the Université de Liège, where he collaborated with Philippe Ghosez, and a further year at Rutgers University in Karin M. Rabe's group, he joined the Universidad de Cantabria as a Ramón y Cajal fellow. He was promoted to tenure in 2010.

His most important methodological work is his contribution to the SIESTA project (http://www.icmab.es/siesta). SIESTA is both, a Density-functional Numerical Atomic Orbital (NAO) method and its computer program implementation. The outstanding feature of this method is its capability of limiting computer time and memory scale to increase only linearly with the number of atoms (order-N scaling). He contributed with an automatically optimized quality of the basis set, to the design and implementation interoperability with other first-principles programs. He has highly contributed to the teaching and dissemination of the method by organizing international workshops and preparing a full set of self-explanatory, openly accessible exercises.

He has specialized in the study of ferroelectric size effects in nanostructures, highlighting the role of the often neglegted depolarizing field in ferroelectric thin films. He has also set the standards for the computation of band offsets and Schottky barriers from first-principles. Always trying to collaborate hand-by-hand with experimental groups, he predicted the formation of domains of closure in ferroelectric ultrathin films and superlattices (confirmed experimentally three years later), and the sequence of growth of Ruddlesden-Popper series (confirmed experimentally ten years later). As invited researcher at University of California Berkeley, he recently predicted the formation of polar skyrmions and complex topological polar textures in ferroelectric superlattices.

Currently, he is involved in the development of “second-principles” methods. The goal is to achieve simulations of tens of thousands of atoms at operating conditions (finite temperature), describing the coupled dynamics of ions and relevant electronic degrees of freedom, and accessing scales and physical phenomena that have never been investigated so far with atomistic details and first-principles accuracy. 

For his achievements, he was frequently invited to the most important international conferences. He wrote two monographs in his field of research.

VIEW ABSTRACT