[23p-B201-1~12] 10.4 Spintronics in semiconductor, topological material, superconductor, and multiferroics

▼ [23p-B201-3] “Ferron” excitations of the ferroelectric order

〇(P)Ping Tang¹, Ryo Iguchi², Ken-ichi Uchida^2,3, Gerrit E.W. Bauer^1,3,4,5,6 (1.AIMR, Tohoku Univ., 2.NIMS, Tsukuba, 3.IMR, Tohoku Univ., 4.CSRN, Tohoku Univ., 5.ZIAM, Univ. of Groningen, 6.KITS, Univ. of the Chinese Academy of Sciences)

Keywords:ferroelectrics

Ferromagnets and ferroelectrics are ferroic materials that exhibit spontaneous order of magnetic and electric dipoles below a critical temperature, respectively. The quasi-particle excitations of magnetic order are magnons that carry energy as well as elementary magnetic dipoles or spins. The transport of spin and heat by magnons has been extensively studied over the past decade in spintronics. However, to our best knowledge, the quasi-particles and associated transport in ferroelectrics have so far remained unexplored. Here we have formulated the bosonic excitations, termed "ferron", in displacive ferroelectrics that carry elementary electric dipoles besides enenrgy from the phenomenological Landau-Ginzburg-Devonshire theory. These ferrons emerge from the concerted action of anharmonicity and broken inversion symmetry. In contrast to magnons, the transverse excitations of the magnetic order, the ferrons in displacive ferroelectrics are longitudinal with respect to the ferroelectric order. Based on the ferron spectrum, we predict temperature dependent pyroelectric and electrocaloritc properties, electric-field-tunable heat and polarization transport, and ferron-photon hybridization.