Related papers: Magnetic-induced phonon anisotropy in ZnCr$_2$O$_4…
We study the magnetically-induced phonon splitting in cubic ACr$_2$O$_4$ (A=Mg, Zn, Cd, Hg) spinels from first principles, and demonstrate that the sign of the splitting, which is experimentally observed to be opposite in CdCr$_2$O$_4$…
Spin-phonon coupling and magnetodielectric effects of ZnCr2Se4 were investigated by means of infrared (IR) spectroscopy as a function of temperature and magnetic field. ZnCr2Se4 is dominated by ferromagnetic exchange but undergoes…
The spin-lattice coupling plays an important role in strongly frustrated magnets. In ZnCr$_2$O$_4$, an excellent realization of the Heisenberg antiferromagnet on the ``pyrochlore'' network, a lattice distortion relieves the geometrical…
Detailed far-infrared spectra of the optical phonons are reported for antiferromagnetic MnO. Eigenfrequencies, phonon damping and effective plasma frequencies are studied as a function of temperature. Special attention is paid to the phonon…
First-principles calculations reveal large zone-center spin-phonon coupling and magnetically-driven phonon anisotropy in cubic perovskites Sr$M$O$_3$ ($M$=V,Cr,Mn,Fe,Co). In particular, the frequency and splitting of the polar Slater mode…
We demonstrate that the onset of complex spin orders in ACr$_2$O$_4$ spinels with magnetic A$=$Co, Fe and Cu ions lowers the lattice symmetry. This is clearly indicated by the emergence of anisotropic lattice dynamics -- as evidenced by the…
Using a combination of first-principles and magnetization-dynamics calculations, we study the effect of the intense optical excitation of phonons on the magnetic behavior in insulating magnetic materials. Taking the prototypical…
We study magnetic excitations in vanadium spinel oxides AV$_2$O$_4$ (A=Zn, Mg, Cd) using two models: first one is a superexchange model for vanadium S=1 spins, second one includes in addition spin-orbit coupling, and crystal anisotropy. We…
We show that the magnetic anisotropy in spinel-structure CoCr$_2$O$_4$ thin films exhibits a strain dependence in which compressive strain induces an out-of-plane magnetic easy axis and tensile strain an in-plane easy axis, exactly opposite…
We present an elaborate electron-spin resonance study of the low-energy dynamics and magnetization in the ordered phase of the magnetically frustrated spinel ZnCr$_2$O$_4$. We observe several resonance modes corresponding to different…
A magneto-optical survey was conducted for HgCr$_2$O$_4$ powder samples under pulsed high magnetic fields of up to 55 T. Intensity changes in magnetic fields observed for the exciton-magnon-phonon optical transition spectra coincide well…
We calculate the structural, electronic, and magnetic properties of MnO from first principles, using the full-potential linearized augmented planewave method, with both local-density and generalized-gradient approximations to exchange and…
In the first part we investigate in detail if the Bose-Einstein condensation scenario for magnons can quantitatively explain the observed field-induced magnetic ordering in TlCuCl$_3$. We use a bond-operator approach to map the spin system…
MnV$_2$O$_4$ in the spinel structure is known to exhibit coupled orbital and spin ordering, and its Raman spectra show interesting anomalies in its low-temperature phase. With a goal to explain this behavior involving coupled spins and…
A detailed investigation of phonon excitations and charge carrier dynamics in single crystals of Fe_{1-x}Cu_{x}Cr_{2}S_{4} (x = 0, 0.2, 0.4, 0.5) has been performed by using infrared spectroscopy. In FeCr_{2}S_{4} the phonon eigenmodes are…
Indirect long range interactions between localized magnetic moments are in metals mediated by itinerant electrons. In insulators and semi-conductor, such interactions need to be small, if not negligible, due to the absence of mediating…
We propose a mechanism to obtain chiral phonon-like excitations from the bond-dependent magnetoelastic couplings in the absence of out-of-plane magnetization and magnetic fields. By mapping the hybrid excitation to its phononic analog, we…
A number of recent experiments exhibit electronic anisotropy in the iron pnictides, and there is a growing body of experimental evidence that its origin is related to orbital ordering in Fe d_{xz} and d_{yz} orbitals. We examine this…
Magnetic anisotropy phenomena in bimetallic antiferromagnets Mn$_2$Au and MnIr are studied by first-principles density functional theory calculations. We find strong and lattice-parameter dependent magnetic anisotropies of the ground state…
A novel general method of describing the spin-lattice interactions in magnetic solids was proposed in terms of first principles calculations. The spin exchange and Dzyaloshinskii-Moriya interactions as well as their derivatives with respect…