We are studying the electronic structures of new and advanced materials. We are using synchrotron radiation to perform soft x-ray emission and absorption spectroscopy of systems like biomaterials, superconductors and transition metal compounds.

Israel Pérez

Israel Perez



  • University of Saskatchewan
    Saskatoon, Saskatchewan
    Postdoctoral Position
    (Condensed Matter)
    December 2013
  • Scientific Research and Superior Education Centre of Ensenada (CICESE)
    Ensenada, Baja California, México
    Research Stay (Electrical Properties of Molybdenum Oxides)
    Apr.-Aug. 2011
  • Research and Advanced Studies Centre (CINVESTAV)
    Mérida Yucatán, México
    Ph. D. (Condensed Matter)
    Oct. 2010
  • Physics Institute of the University of Guanajuato
    León Guanajuato, México
    Master (Physics)
    Dec. 2005
  • University of Guadalajara
    Guadalajara Jalisco, México
    Undergraduate (Physics)
    Sept. 2003

Current Affiliation

  • Associate Professor, National Council of Science and Technology (CONACYT), Institute for Engineering and Technology, Universidad Autónoma de Ciudad Juárez, Juárez, Chihuahua, Mexico

Research Projects

Material Science

My research interests involved the growth of superconducting thin films and their characterization. Very recently Japanese investigators discovered a new family of superconductors based on iron-pnictide layers with very interesting properties. Several systems, like FeAs, LaFeO1-xFxAs and BaFe2As2, besides showing critical temperatures ranging from 3 K up to 55 K, present ferromagnetic behavior. However, these new discoveries complicate even more the understanding of superconducting phenomena. The University of Saskatchewan hosts the Canadian Light Source, an ideal tool to study the electronic properties of these novel materials. In particular, I am interested in finding a correlation between the electronic properties and the superconducting ones, such as the critical temperature Tc and/or the critical magnetic field Hc2, of iron-pnictides materials. These investigations could shed light for the creation of more effective microscopic theories.


Our group is planning to grow transition metal and superconducting thin films making use of a physical vapor deposition (PVD) technique. The implementation of the so called electro-beam co-evaporation (EBCE) technique is currently under way. The equipment consists of an ultra-high vacuum chamber where the deposition of the films takes place. The chamber will be equipped with LEED and RHEED techniques, infrared pyrometers, thermocouples, pressure sensors and Quartz Crystal Monitors (QCM) which are used to determine in situ, among other things, the temperature, the crystalline structure, the thickness, the lattice parameters and the atomic concentration of the samples as well as the partial pressure inside the chamber and the temperature of the chemical elements to be evaporated. I will be working on the parts acquisition, the equipment assembly and calibration, and the deposition of the very first films.

Other Projects

Foundations of Physics

For more than thirty years theoretical physicists have struggled to achieve a unified theory that endeavours to explain physical phenomena from the very small scales to very large ones. So far, however, all attempts have failed. Why…? Some people believe that some fundamental principles may be missing. Physical phenomena such as dark matter, dark energy, the asymmetry of matter and antimatter, the ultra high-energy cosmic ray cut-off and the acceleration of space expansion are still wandering in nature with no scientific explanation whatsoever. These are weighty arguments to review the foundations of the two pillars of modern physics, i.e., quantum mechanics and relativity.

My interests in this area are the ontology of space and its implications in physics, in particular quantum mechanics and cosmology. The conception of space unquestionably has a great impact on physical theories. According to the current view, space, particles and fields are thought of as of distinct nature. Space is a non-material substratum for particles and fields to live. However, another way of correlating these objects is by assuming that space is a material continuous medium whose states and excitations are fields and particles, respectively. This view has found its mathematical description in soliton theory and fluid mechanics. In this respect, I am interested in working out both a conceptual framework and a reformulation of physics that becomes useful for a unified theory.

To achieve such goal it is important to unambiguously reveal some of the weaknesses of the foundations of modern physics. My most recent work deals with the existence of a preferred system of reference (PSR). In this essay I discuss that the principle of relativity is not at variance with the PSR. It is elucidated that the notion of vacuum as medium can be held without falling in contradictions with the principle of invariance. In another contribution I discuss the experimental determination of the speed of light. There, it is shown that all experimental techniques designed to measure the speed of any physical entity, actually, measure the two-way or round trip speed. This implies that the one-way speed of light cannot be experimentally determined and therefore the second postulate of special relativity cannot be falsified.


  • Analysis of higher-order harmonics in YBCO thin films by the mutual inductive technique, May 6th 2011, CICESE. México



  • CONACYT Postdoctoral Scholarship (Aug. 2011 - Jul. 2013)


  • CINVESTAV Poster Award (Sept. 2009)
  • CINVESTAV Seminar Award (Oct. 2008)
  • CONACYT Ph.D. Scholarship (Sept. 2006)
  • University of Guanajuato "Laureate Master's Degree" (Dec. 2005)
  • University of Guanajuato Scholarship (Sept. 2005)
  • CONACYT Master Scholarship (Sept. 2003)


  • "Outstanding Student Award, University of Guadalajara" (Oct. 2003)


  • Candidate to “National Researcher” for the National System of Researchers (SNI) Mexico (Jan 2013-Dec 2015)
  • Fourth Prize Winner of the international essay contest organized by the Foundational Questions Institute FQXi in USA: "Which of our basic physical assumptions are wrong?". (Nov. 2012)
    Essay: "The Preferred System of Reference Reloaded".
    Link: http://www.fqxi.org/community/essay/winners/2012.1

  • Publications

    1. I. Perez, J. A. McLeod, R. J. Green, R. Escamilla, V. Ortiz, and A. Moewes,
      Electronic Structure of FeSe1-xTex Studied by X-ray Spectroscopy and Density Functional Theory,
      J. Phys. Chem. C, 118 (43), 25150–25157, (2014).

    2. F. Gamboa, Víctor Sosa, I. Pérez, J. A Matutes-Aquino, and A. Moewes,
      Determination of the critical current density in YBa2Cu3O7 thin films measured by the screening technique under two criteria,
      IEEE Trans. on Appl. Supercond. 25(2), (2014).

    3. I. Perez, J. A. McLeod, R. J. Green, R. Escamilla, V. Ortiz, and A. Moewes,
      Electronic structure of Co-substituted FeSe superconductor probed by soft x-ray spectroscopy and density functional theory,
      Physical Review B, 90, 014510 (2014).

    4. Neil W. Johnson, Patrick Vogt, Andrea Resta, Paola De Padova, Israel Perez, David Muir, Ernst Z. Kurmaev, Guy Le Lay, Alexander Moewes,
      The Metallic Nature of Epitaxial Silicene Monolayers on Ag(111),
      Adv. Func. Mat. 24, 5253-5259, (2014).

    5. J. A. Mcleod, E. Z. Kurmaev, I. Perez, A. Moewes, V. K. Anand, P. Kanchana Perera, and D. C. Johnston,
      Electronic Structure of Copper Pnictides: Influence of Different Cations and Pnictogens,
      Phys. Rev. B 88, 014508, (2013).

    6. Israel Pérez,
      On the experimental determination of the one-way speed of light,
      Eur. J. Phys. 32 993-1005, (2011).

    7. Israel Pérez, Fidel Gamboa and Víctor Sosa,
      Study of higher-order harmonics of complex ac susceptibility in YBa2Cu3O7-δ thin films by the mutual inductive method.
      Physica C, 470, 2061-2066, (2010)

    8. Israel O. Pérez-López, Fidel Gamboa and Víctor Sosa,
      Critical current density and ac harmonic voltage generation in YBa2Cu3O7-δ thin films by the screening technique.
      Proceedings of the 9th International Conference on Materials and Mechanisms of Superconductivity Tokyo Japan Sept 7-12, 2009,
      Published in Physica C, 470, S972-S974, (2010).

    9. Modesto Sosa et al.,
      Measurement of the Magnetic Susceptibility in Liquid Substances in the Physics Laboratory.
      Revista Mexicana de Física E, 52,11, 1 (2006),

    10. M.A. Reyes et al. (E690 Collaboration)
      Exotic baryon searches in 800 GeV/c pppX,
      AIP Conf. Proc. 814, 356-360, (2006).
      From the XI International Hadron Spectroscopy, Rio de Janeiro Brazil 21-26 August (2005); A. Reis, C. Gobel, J. de Sá Borges and J. Magnin, Eds.