Minimal Zeeman field requirement for a topological transition in superconductors

Platforms for creating Majorana quasiparticles rely on superconductivity and breaking of time-reversal symmetry. By studying continuous deformations to known trivial states, we find that the relationship between superconducting pairing and time reversal breaking imposes rigorous bounds on the topology of the system. Applying these bounds to s-wave systems with a Zeeman field, we conclude that a topological phase transition requires that the Zeeman energy at least locally exceed the superconducting pairing by the energy gap of the full Hamiltonian. Our results are independent of the geometry and dimensionality of the system.

Особенности перемагничивания обменно-связанных пленочных структур Tb-Co/FeNi в температурном интервале, включающем точку компенсации ферримагнитного слоя

The magnetic properties of exchange-coupled Tb-Co/FeNi film structures obtained by magnetron sputtering were studied in a wide temperature range. It was shown that a decrease in the Zeeman energy when approaching the compensation temperature of the ferrimagnetic layer was accompanied by a change in the sequence of magnetization reversal of the layers. The efficiency of the interlayer exchange interaction varies with temperature very little.

Dynamics of the Magnetization of a Single-Domain Deformed Soft Magnetic Ferromagnet

On the basis of the quantum model taking into account the Zeeman energy and the energy of the crystal field, dynamic equations of Landau — Lifshitz — Hilbert type for the magnetization of the deformed singledomain α-Fe crystal are obtained. The domain deformation is taken into account in the framework of a linear approximation. The equations of motion are solved numerically using the Adams — Multon, Rosenbrock, and RADAU5 methods. It is shown that for some values of the model parameters, the dependence of the magnetization on the strength of an external magnetic field has the characteristic form of a hysteresis loop. Qualitative agreement of the model dependence of the coercive force on the applied longitudinal pressure with similar experimental data for various steel grades Durehete 1055, AS1548746OR, X70, 11HN3D is obtained.

Условия возникновения спонтанной осциллирующей магнитной релаксации в синтетических ферримагнетиках Pt/Co/Ir/Co/Pt

We had established that the non-monotonic magnetic relaxation appeared, when two or three magnetic fields, switching between stable magnetization states, coincide with each other, in Pt/Co/Ir/Co/Pt synthetic ferrimagnets with perpendicular magnetic anisotropy. Switching fields between stable magnetization states depend on sum of exchange interlayer energy, Zeeman energy and magnetization reversal energy barrier of each layer. This total energy depends on layers thickness and temperature. We had shown that with choose of temperature and free layer thickness we can achieve double or triple points on energy states diagram, which is reason of nonmonotonic magnetization relaxation.

Theoretical Equations of Zeeman Energy Levels for Distorted Metal Complexes with 3T1 Ground Terms

The theoretical equations of Zeeman energy levels, including the zero-field energies and the first- and second-order Zeeman coefficients, have been obtained in closed form for nine states of the 3 T 1 ( g ) ground term, considering the axial ligand-field splitting and the spin-orbit coupling. The equations are expressed as the functions of three independent parameters, Δ , λ , and κ , where Δ is the axial ligand-field splitting parameter, λ is the spin-orbit coupling parameter, and κ is the effective orbital reduction factor, including the admixing. The equations are useful in simulating magnetic properties (magnetic susceptibility and magnetization) of the complexes with 3 T 1 ( g ) ground terms, e.g., octahedral vanadium(III), octahedral low-spin manganese(III), octahedral low-spin chromium(II), and tetrahedral nickel(II) complexes.