相关论文: Generalised Longitudinal Susceptibility for Magnet…
A magnetic monopole in spin ice is a novel quasiparticle excitation in condensed matter physics, and we found that the ac frequency dependent magnetic susceptibility $\chi(\omega)$ in the two-dimensional (2D) spin ice (so-called kagom\'{e}…
A theory for frequency-dependent magnetic susceptibility \chi(\omega) is developed for thermally activated magnetic monopoles in kagome ice. By mapping this system to a two-dimensional (2D) Coulomb gas and then to a sine-Gordon model, we…
Proceeding from the more general to the more concrete, we propose an equilibrium field theory describing spin ice systems in terms of topological charges and magnetic monopoles. We show that for a spin ice on a graph, the entropic…
Here we calculate the dynamic susceptibility and dynamic correlation function in spin ice using the model of emergent magnetic monopoles. Calculations are based on a method originally suggested for the description of dynamic processes in…
Theory predicts the low-temperature magnetic excitations in spin ices consist of deconfined magnetic charges, or monopoles. A recent transverse-field (TF) muon spin rotation (muSR) experiment [S T Bramwell et al, Nature 461, 956 (2009)]…
Magnetic monopoles are hypothesised elementary particles connected by Dirac strings that behave like infinitely thin solenoids. Despite decades of searches, free magnetic monopoles and their Dirac strings have eluded experimental detection,…
The single-ion anisotropy and magnetic interactions in spin-ice systems give rise to unusual non-collinear spin textures, such as Pauling states and magnetic monopoles. The effective spin correlation strength ($J_{eff}$) determines the…
An important and continuing theme of modern solid state physics is the realization of exotic excitations in materials (e.g. quasiparticles) that have no analogy (or have not yet been observed) in the actual physical vacuum of free space.…
Artificial spin ice systems are metamaterials composed of interacting nanomagnets arranged on a lattice, exhibiting geometrical frustration and emergent phenomena such as monopole excitations. We explore magnetization dynamics and monopole…
Spin ice illustrates many unusual magnetic properties, including zero point entropy, emergent monopoles and a quasi liquid-gas transition. To reveal the quantum spin dynamics that underpin these phenomena is an experimental challenge. Here…
In this work, we show that, due to the alternating orientation of the spins in the ground state of the artificial square spin ice, the influence of a set of spins at a certain distance of a reference spin decreases faster than the expected…
Frustration in magnetic systems is fertile ground for complex behaviour, including unconventional ground states with emergent symmetries, topological properties, and exotic excitations. A canonical example is the emergence of…
At low temperatures, spin dynamics in ideal spin ice is due mainly to dilute, thermally excited magnetic monopole excitations. I consider how these will affect the dynamics of a nuclear spin (the same theory applies to muon spin resonance…
Excitations from a strongly frustrated system, the kagome ice state of the spin ice Dy2Ti2O7 under magnetic fields along a [111] direction, have been studied. They are theoretically proposed to be regarded as magnetic monopoles. Neutron…
We study the magnetic excitations of a square lattice spin-ice recently produced in an artificial form, as an array of nanoscale magnets. Our analysis, based upon the dipolar interaction between the nanomagnetic islands, correctly…
The temperature-dependent uniform magnetic susceptibility of interacting electrons in one dimension is calculated using several methods. At low temperature, the renormalization group reaveals that the Luttinger liquid spin susceptibility…
Using the Dirac string formalism for monopoles we expose an extensive analogy between magnetic monopole excitations in the dumbbell model of spin ice and those of the vacuum. In both cases the Dirac strings are defined in the space-time of…
Here we study the statistical properties of two-dimensional spin ice in its ground state by the Monte Carlo simulation method. Using a new sampling algorithm, we show that the short-range ice rule in two dimensions gives rise to long-range…
We have calculated the low-field magnetic susceptibility $\chi$ of a system consisting of non-interacting mono-dispersed nanoparticles using a classical statistical approach. The model makes use of the assumption that the axes of symmetry…
Magnetic monopole unpairing as a function of external magnetic fields is presented as a fingerprint of this emergent quasiparticles freedom in a two-dimensional artificial spin ice system. Such freedom, required for example for further…