Erratum: Orbital Angular Momentum of Magnons in Collinear Magnets [Phys. Rev. Lett. 129, 167202 (2022)].

This corrects the article DOI: 10.1103/PhysRevLett.129.

Orbital Angular Momentum of Magnons in Collinear Magnets.

We study the orbital angular momentum of magnons for collinear ferromagnet (FM) and antiferromagnetic (AF) systems with nontrivial networks of exchange interactions. The orbital angular momentum of magnons for AF and FM zigzag and honeycomb lattices becomes nonzero when the lattice contains two inequivalent sites and is largest at the avoided-crossing points or extremum of the frequency bands. Hence, the arrangement of exchange interactions may play a more important role at producing the orbital angular momentum of magnons than the spin-orbit coupling energy and the resulting noncollinear arrangement of spins.

Exact results for the orbital angular momentum of magnons on honeycomb lattices.

We obtain exact results for the orbital angular momentum (OAM) of magnons at the high symmetry points of ferromagnetic (FM) and antiferromagnetic (AF) honeycomb lattices in the presence of Dzyallonshinskii-Moriya (DM) interactions. For the FM honeycomb lattice in the absence of DM interactions, the values of the OAM at the corners of the Brillouin zone (BZ) (k1∗=(0,23/9)2π/a,k2∗=(1/3,3/9)2π/a,…) are alternately±3ℏ/16for both magnon bands. The presence of DM interactions dramatically changes those values by breaking the degeneracy of the two magnon bands.

Two methods to study inelastic neutron-scattering measurements based on() versus(,) applied to the magnetic open honeycomb lattice TbIrGa.

This work describes two methods to fit the inelastic neutron-scattering spectrum(,) with wavevectorand frequency. The common and well-established method extracts the experimental spin-wave branches() from the measured spectra(,) and then minimizes the difference between the observed and predicted frequencies. Whenbranches of frequencies are predicted but the measured frequencies overlap to produce onlybranches, the weighted average of the predicted frequencies must be compared to the observed frequencies.

Cluster Frustration in the Breathing Pyrochlore Magnet LiGaCr_{4}S_{8}.

We present a comprehensive neutron scattering study of the breathing pyrochlore magnet LiGaCr_{4}S_{8}. We observe an unconventional magnetic excitation spectrum with a separation of high- and low-energy spin dynamics in the correlated paramagnetic regime above a spin-freezing transition at 12(2) K. By fitting to magnetic diffuse-scattering data, we parametrize the spin Hamiltonian.

Observation of a Large Magnetic Anisotropy and a Field-Induced Magnetic State in SrCo(VO)(OH): A Structure with a Quasi One-Dimensional Magnetic Chain.

A new member of the descloizite family, a cobalt vanadate, SrCo(VO)(OH), has been synthesized as large single crystals using high-temperature and high-pressure hydrothermal methods. SrCo(VO)(OH) crystallizes in the orthorhombic crystal system in space group 222 with the following unit cell parameters: = 6.0157(2) Å, = 7.

Tuning Magnetic Soliton Phase via Dimensional Confinement in Exfoliated 2D CrNbS Thin Flakes.

Thin flakes of CrNbS are fabricated successfully via microexfoliation techniques. Temperature-dependent and field-dependent magnetizations of thin flakes with various thicknesses are investigated. When the thickness of the flake is around several hundred nanometers, the softening and eventual disappearance of the bulk soliton peak is accompanied by the appearance of other magnetic peaks at lower magnetic fields.

Giant Spin-Driven Ferroelectric Polarization in BiFeO₃ at Room Temperature.

The spin-driven polarizations of type-I multiferroics are veiled by the preexisting ferroelectric (FE) polarization. Using first-principles calculations combined with a spin model, we uncover two hidden but huge spin-driven polarizations in the room-temperature multiferroic BiFeO(3). One is associated with the global inversion symmetry broken by a FE distortion, and the other is associated with the local inversion symmetry broken by an antiferrodistortive octahedral rotation.

Ground-state and spin-wave dynamics in brownmillerite SrCoO(2.5)--a combined hybrid functional and LSDA + U study.

We theoretically investigate the ground-state magnetic properties of the brownmillerite phase of SrCoO2.5. Strong correlations between Co d electrons are treated within the local spin density approximations of density functional theory (DFT) with Hubbard U corrections (LSDA+U), and results are compared with those using the Heyd-Scuseria-Ernzerhof (HSE) functional.

Terahertz spectroscopy of spin waves in multiferroic BiFeO3 in high magnetic fields.

We have studied the magnetic field dependence of far-infrared active magnetic modes in a single ferroelectric domain BiFeO3 crystal at low temperature. The modes soften close to the critical field of 18.8 T along the [001] (pseudocubic) axis, where the cycloidal structure changes to the homogeneous canted antiferromagnetic state and a new strong mode with linear field dependence appears that persists at least up to 31 T.

Neutron-diffraction evidence for the ferrimagnetic ground state of a molecule-based magnet with weakly coupled sublattices.

The diruthenium compound [Ru(2)(O(2)CMe)(4)](3)[Cr(CN)(6)] contains two weakly coupled, ferrimagnetically ordered sublattices occupying the same volume. Due to the weak, antiferromagnetic dipolar interaction K(c) ≈ 5 × 10(-3) meV between sublattices, a small magnetic field H(c) ∼ K(c)/μ(B) ≈ 800 Oe aligns the sublattice moments. Powder neutron-diffraction measurements on a deuterated sample confirm an earlier prediction that the sublattice moments are restricted by the anisotropy of the diruthenium 'paddle-wheels' to the cubic diagonals.

Phase diagram of CuCrO2 in a magnetic field.

A simplified model is used to construct the magnetic phase diagram of CuCrO(2) as a function of magnetic field and easy-axis anisotropy. Neglecting the weak interactions between hexagonal layers, CuCrO(2) is predicted to undergo transitions between three different 3-sublattice (SL) phases with increasing field: from a chiral, non-collinear phase that exhibits multiferroic behavior, to a collinear phase, to a non-chiral, non-collinear phase. The phase diagram also contains 1-SL, 4-SL, and 5-SL collinear phases, some of which may be accessible in the nonstoichiometric compound CuCrO(2+δ).

Phase diagram of a geometrically frustrated triangular-lattice antiferromagnet in a magnetic field.

The magnetic phase diagram of a geometrically frustrated triangular-lattice antiferromagnet is evaluated as a function of magnetic field and anisotropy using a trial spin state built from harmonics of a fundamental ordering wave vector. A noncollinear incommensurate state, observed to be chiral and ferroelectric in CuFeO2, appears above a collinear state with 4 sublattices (SLs). The apparent absence of multiferroic behavior for predicted chiral, noncollinear 5-SL states poses a challenge to theories of the ferroelectric coupling in CuFeO2.

Magnetic compensation and ordering in the bimetallic oxalates: why are the 2D and 3D series so different?

Although the exchange coupling and local crystal-field environment are almost identical in the two-dimensional (2D) and three-dimensional (3D) series of bimetallic oxalates, those two classes of materials exhibit quite different magnetic properties. Using mean-field theory to treat the exchange interaction, we evaluate the transition temperatures and magnetizations of the 3D Fe(II)Fe(III) and Mn(II)Cr(III) bimetallic oxalates. Because of the tetrahedral coordination of the chiral anisotropy axis, the 3D bimetallic oxalates have lower transition temperatures than their 2D counterparts, and much stronger anisotropy is required to produce magnetic compensation in the 3D Fe(II)Fe(III) compounds.

Spin waves in antiferromagnetically coupled bimetallic oxalates.

Bimetallic oxalates are molecule-based magnets with transition-metal ions M(II) and M(')(III) arranged on an open honeycomb lattice. Performing a Holstein-Primakoff expansion, we obtain the spin-wave spectrum of antiferromagnetically coupled bimetallic oxalates as a function of the crystal-field angular momentum L(2) and L(3) on the M(II) and M(')(III) sites. Our results are applied to the Fe(II)Mn(III), Ni(II)Mn(III) and V(II)V(III) bimetallic oxalates, where the spin-wave gap varies from 0 meV for quenched angular momentum to as high as 15 meV.

Inverse Jahn-Teller transition in bimetallic oxalates.

Because of the competition between the spin-orbit coupling and the Jahn-Teller (JT) energies in Fe(II)Fe(III) bimetallic oxalates, we theoretically predict that an undistorted phase with C3 symmetry about each Fe site may be recovered at low temperatures. Both lower and upper JT transitions bracketing the ferrimagnetic transition temperature Tc are predicted for compounds that exhibit magnetic compensation. Comparisons with recent measurements and first-principles calculations provide strong evidence for the inverse JT transition below Tc.

Giant negative magnetization in a layered organic magnet.

Bimetallic oxalates are a class of layered organic magnets with transition metals M(II) and M'(III) coupled by oxalate molecules in an open honeycomb structure. Energy, structure, and symmetry considerations are used to construct a reduced Hamiltonian, including exchange and spin-orbit interactions, that explains the giant negative magnetization in some of the ferrimagnetic Fe(II)Fe(III) compounds. We also provide new predictions for the spin-wave gap, the effects of uniaxial strain, and the optical flipping of the negative magnetization in Fe(II)Fe(III) bimetallic oxalates.

Nature of perpendicular-to-parallel spin reorientation in a Mn-doped GaAs quantum well: canting or phase separation?

It is well known that the magnetic anisotropy in a compressively strained Mn-doped GaAs film changes from perpendicular to parallel with increasing hole concentration p. We study this reorientation transition at T=0 in a quantum well with delta-doped Mn impurities. With increasing p, the angle theta that minimizes the energy E increases continuously from 0 (perpendicular anisotropy) to pi/2 (parallel anisotropy) within some range of p.

Magnetic susceptibility and order parameter of the spin-glass-like phase of the double-exchange model.

The magnetic susceptibility and Edwards-Anderson order parameter q of the spin-glass-like (SGL) phase of the double-exchange model are evaluated in the weak-coupling or RKKY limit. Dynamical mean-field theory is used to show that q = M(T/T(SGL))2, where M is the classical Brillouin function and T(SGL) is the SGL transition temperature. The correlation length of the SGL phase is determined by a correlation parameter Q that maximizes T(SGL) and minimizes the free energy.

Transition temperature of a magnetic semiconductor with angular momentum j.

We employ dynamical mean-field theory to identify the materials properties that optimize T(c) for a generalized double-exchange model. We reach the surprising conclusion that T(c) achieves a maximum when the band angular momentum j equals 3/2 and when the masses in the m(j) = +/- 1/2 and +/-3/2 and subbands are equal. However, we also find that T(c) is significantly reduced as the ratio of the masses decreases from one.