A multiferroic material to search for the permanent electric dipole moment of the electron

We suggested using strong internal electric field in multiferroic Eu_0.5Ba_0.5TiO₃ for the search of permanent electric dipole moment (EDM) of the electron. According to standard model of particles its value should be of order of 10^–40 e.cm. Recently it has been shown that spontaneous violation of charge parity symmetry is much larger then it follows from the standard model, therefore this model needs an extension. New particle theories propose EDM of electrons 8 or 12 orders of magnitude larger then the standard model. The physicists try to measure EDM of electron already 40 years, unfortunately fruitlessly. They reached sensitivity of only 10^–27 e.cm. We have shown that in multiferroic Eu_0.5Ba_0.5TiO₃ the sensitivity should be one order of magnitude higher. In case of successful determination of EDM value it will be possible to prove and specify new theories going beyond the standard model. We synthesized this material, prepared ceramic samples suitable for this EDM measurement and characterized its magnetic and dielectric properties. Theory has been done by our foreign partners.

Temperature dependence of ac magnetic susceptibility, χ, at various static magnetic fields and a frequency of 214 Hz. The inset shows magnetization curves at various temperatures. We note that no hysteresis in magnetization was observed.

¹Institut für Festkörperforschung, Forschungszentrum Jülich GmbH, 52425 Jülich and JARA-FIT, Germany
²Institute of Physics ASCR, Na Slovance 2, 182 21 Prague 8, Czech Republic
³Charles University, Faculty of Mathematics and Physics, Department of Condensed Matter Physics, Ke Karlovu 5, 121 16 Prague 2, Czech Republic
⁴Czech Geological Survey, Geologická 6, 152 00 Prague 5, Czech Republic
⁵Yale University, Department of Physics, PO Box 208120, New Haven, Connecticut 06520-8120, USA
⁶Materials Department, University of California, Santa Barbara, California 93106-5050, USA