相关论文: Magnetoelectric spectroscopy of spin excitations i…
We theoretically study origins of the ferroelectricity in the multiferroic phases of the rare-earth (R) Mn perovskites, RMnO3, by constructing a realistic spin model including the spin-phonon coupling, which reproduces the entire…
We use symmetry analysis and first principles calculations to show that the linear magnetoelectric effect can originate from the response of orbital magnetic moments to the polar distortions induced by an applied electric field. Using…
Motivated by recent measurements on CuGeO$_3$ the spectrum of magnetic excitations of an antiferromagnetic $S=\frac{1}{2}$ chain with alternating coupling strength is investigated. Wave vector dependent magnons and a continuum with square…
We present a terahertz spectroscopic study of magnetic excitations in ferroelectric antiferromagnet BiFeO3. We interpret the observed spectrum of long-wavelength magnetic resonance modes in terms of the normal modes of the material's…
We use neutron scattering to determine spin excitations in single crystals of nonsuperconducting Li1-xFeAs throughout the Brillouin zone. Although angle resolved photoemission experiments and local density approximation calculations suggest…
Flexoelectricity is the linear response of polarization to a strain gradient. Here we address the simplest class of dielectrics, namely elemental cubic crystals, and we prove that therein there is no extrinsic (i.e. surface) contribution to…
The two-layer square lattice quantum antiferromagnet with spins 1/2 shows a zero-field magnetic order-disorder transition at a critical ratio of the inter-plane to intra-plane couplings. Adding a uniform magnetic field tunes the system to…
The magnetoelectric coupling, i.e., cross-correlation between electric and magnetic orders, is a very desirable property to combine functionalities of materials for next-generation switchable devices. Multiferroics with spin-driven…
The contribution of the polarization associated with the noncollinear parts of spins in the dielectric permeability tensor of multiferroic materials is considered. As the equilibrium state, we consider the systems of parallel spins, so we…
A joint theoretical approach, combining macroscopic symmetry analysis with microscopic methods (density functional theory and model cluster Hamiltonian), is employed to shed light on magnetoelectricity in Ba2CoGe2O7. We show that the…
We report on the spin waves and crystal field excitations in single crystal LiFePO$_4$ by inelastic neutron scattering over a wide range of temperatures, below and above the antiferromagnetic transition of this system. In particular, we…
We study magneto-elastic effects in crystals of magnetic molecules. Coupled equations of motion for spins and sound are derived and the possibility of strong resonant magneto-acoustic coupling is demonstrated. Dispersion laws for…
In this paper we study magnetoelectric effects in two-dimensional magnetic bilayers and introduce the notion of a layer dipole magnetoelectric polarizability. This magnetoelectric polarizability describes the magnetization response to an…
The magnon and optical phonon spectrum of an incommensurate multiferroic such as BiFeO3 is considered in the framework of a phenomenological Landau theory. The resulting spin wave spectrum is quite distinct from commensurate substances due…
The spin-wave excitations of the multiferroic $\rm MnWO_4$ have been measured in its low-temperature collinear commensurate phase using high-resolution inelastic neutron scattering. These excitations can be well described by a Heisenberg…
The magnetic field induced rearrangement of the cycloidal spin structure in ferroelectric mono-domain single crystals of the room-temperature multiferroic BiFeO$_3$ is studied using small-angle neutron scattering (SANS). The cycloid…
We report on the effects of spin fluctuations, magnetic ordering, and external magnetic field on the dielectric constant of the ferromagnet SeCuO3, and the antiferromagnet TeCuO3. A model based on the coupling between uniform polarization…
We investigate the bulk magnetic, electron paramagnetic resonance, and magneto-optical properties of {Ni4Mo12}, a magnetic molecule with antiferromagnetically coupled tetrahedral {Ni4Mo12} in a diamagnetic molybdenum matrix. The…
Terahertz and far-infrared electric and magnetic responses of hexagonal piezomagnetic YMnO3 single crystals are investigated. Antiferromagnetic resonance is observed in the spectra of magnetic permeability mu_a [H(omega) oriented within the…
Whenever the elastic energy of a solid depends on magnetic field, there is a magnetostrictive response. Field-linear magnetostriction implies piezomagnetism and vice versa. Here, we show that Mn$_3$Sn, a non-collinear antiferromanget with…