相关论文: Emergent surface multiferroicity

We use symmetry analysis and density functional theory to characterize antiferromagnetic (AFM) materials which have a finite equilibrium magnetization density on particular surface terminations. A nonzero magnetic dipole moment per unit…

We use symmetry analysis and density functional theory to show that changes in magnetic order at a surface with respect to magnetic order in the bulk can be generically determined by considering local magnetoelectric responses of the…

Some magnetoelectric multiferroics have a canted spin structure that can be described by a Dzyaloshinkii-Moriya coupling. We calculate properties and features expected for surface and bulk magnon polaritons in such media with a linear…

Altermagnets host an array of magnetic multipoles, which are often visualized and studied in the reciprocal space. In the real space, the relative phase of the multipoles of the spin-density around atoms determines whether a system is an…

Most previous investigations have shown that the surface of a ferromagnetic material may have antiferromagnetic tendencies. However, experimentally the opposite effect has been recently observed: ferromagnetism appears in some nano-sized…

We uncover a new pathway towards multiferroicity, showing how magnetism can drive ferroelectricity without relying on inversion symmetry breaking of the magnetic ordering. Our free-energy analysis demonstrates that any commensurate…

We use a combination of density functional theory and Monte Carlo calculations to calculate the surface magnetization in magnetoelectric $\mathrm{Cr_2O_3}$ at finite temperatures. Such antiferromagnets, lacking both inversion and…

RuO2, widely proposed as a prototypical altermagnet, remains intensely debated with regard to its magnetic nature. Here, we demonstrate that RuO2 is non-magnetic in the bulk, but possesses a spontaneous surface ferrimagnetic order. Using…

Multiferroic materials, characterized by the coexistence of ferroelectricity and ferromagnetism, may unveil band structures suggestive of complex phenomena and new functionalities. In this Letter, we analyze the band structure of EuO in its…

In honor of Igor Dzyaloshinskii on his 90th birthday, we revisit his pioneering work on the linear magnetoelectric effect in light of the modern theory of ferroelectric polarization. We show that the surface magnetic dipole moment…

Spin-splitting antiferromagnets with spin-polarized band structures in momentum space have garnered intensive research attention due to their zero net magnetic moments, ultras fast spin dynamics as conventional antiferromagnets, and…

We present a theoretical study of the onset of electric polarization close to a surface in magnetic materials and in thin films and multilayers. We consider two different paths that lead to the onset of multiferroic behavior at the boundary…

Nonlinear optics plays important roles in the research of fundamental physics and the applications of high-performance optoelectronic devices. The bulk nonlinear optical responses arise from the uniform light absorption in…

We present a theory for surface polaritons on ferroelectric-antiferromagnetic materials with canted spin structure. Canting is assumed to be due to a Dzyaloshinkii-Moriya interaction with the electric polarisation and weak ferromagnetism…

This article presents a survey of many nontrivial effects connected with the coupling of electric and magnetic degrees of freedom in solids -- the field initiated by I.~E.~Dzyaloshinskii in 1959. I briefly consider the main physics of…

We demonstrate computationally the existence of magnetoelectric multipoles, arising from the second order term in the multipole expansion of a magnetization density in a magnetic field, in noncentrosymmetric magnetic metals. While…

We discuss the second-order magnetoelectric effect, in which a quadratic or bilinear electric field induces a linear magnetization, in terms of the ferroic ordering of magnetic octupoles. We present the decomposition of a general rank-3…

A general formula for the average vector potential of bulk periodic systems is proposed and shown to set the boundary conditions at magnetic interfaces. For antiferromagnetic materials, the study reveals a unique relation between the…

Magnetoelectric multiferroics are highly sought after for applications in low-power electronics and for advancing fundamental research, including axion insulators and dark matter detection. However, achieving a combination of ferroic spin…

Altermagnets are an emergent class of materials combining features of ferro- and antiferro-magnetic materials. They have spin-separated bands normally associated with ferromagnets, but a vanishing net magnetization. Moreover the symmetries…