REAL

Spin-induced polarizations and nonreciprocal directional dichroism of the room-temperature multiferroicBiFeO3

Fishman, Randy S. and Lee, Jun Hee and Bordács, Sándor and Kézsmárki, István and Nagel, Urmas and Rõõm, Toomas (2015) Spin-induced polarizations and nonreciprocal directional dichroism of the room-temperature multiferroicBiFeO3. Physical Review B, 92 (9). ISSN 1098-0121

[img]
Preview
Text
1506.04595.pdf - Submitted Version

Download (1MB) | Preview

Abstract

A microscopic model for the room-temperature multiferroic BiFeO3 that includes two Dzyaloshinskii- Moriya interactions and single-ion anisotropy along the ferroelectric polarization predicts both the zero-field spectroscopic modes as well as their splitting and evolution in a magnetic field. Due to simultaneously broken time-reversal and spatial-inversion symmetries, the absorption of light changes as the magnetic field or the direction of light propagation is reversed. We discuss three physical mechanisms that may contribute to this absorption asymmetry known as nonreciprocal directional dichroism: the spin current, magnetostriction, and single-ion anisotropy. We conclude that the nonreciprocal directional dichroism in BiFeO3 is dominated by the spin-current polarization and is insensitive to the magnetostriction and easy-axis anisotropy. With three independent spin-current parameters, our model accurately describes the nonreciprocal directional dichroism observed for magnetic field along [1,−1,0]. Since some modes are almost transparent to light traveling in one direction but opaque for light traveling in the opposite direction, BiFeO3 behaves as a room-temperature optical diode at certain frequencies in the gigahertz to terahertz range. Our work demonstrates that an analysis of the nonreciprocal directional dichroism spectra based on an effective spin model supplemented by first-principles calculations can produce a quantitative microscopic theory of the magnetoelectric couplings in multiferroic materials.

Item Type: Article
Subjects: Q Science / természettudomány > QC Physics / fizika > QC06 Physics of condensed matter / szilárdtestfizika
Depositing User: Dr Sándor Bordács
Date Deposited: 29 Sep 2015 12:05
Last Modified: 04 Apr 2023 11:14
URI: http://real.mtak.hu/id/eprint/29221

Actions (login required)

Edit Item Edit Item