相关论文: Observing Monopoles in a Magnetic Analog of Ice
Spin ice materials are magnetic substances in which the spin directions map onto hydrogen positions in water ice. Recently this analogy has been elevated to an electromagnetic equivalence, indicating that the spin ice state is a Coulomb…
Spin ice is a frustrated magnetic system that at low temperatures exhibits a Coulomb phase, a classical spin liquid with topological order and deconfined excitations. This work establishes the presence of a Coulomb phase with coexisting…
We present non-equilibrium physics in spin ice as a novel setting which combines kinematic constraints, emergent topological defects, and magnetic long range Coulomb interactions. In spin ice, magnetic frustration leads to highly degenerate…
One of the most remarkable examples of emergent quasi-particles, is that of the "fractionalization" of magnetic dipoles in the low energy configurations of materials known as "spin ice", into free and unconfined magnetic monopoles…
We investigate the transport properties of itinerant electrons interacting with a background of localized spins in a correlated paramagnetic phase of the pyrochlore lattice. We find a residual resistivity at zero temperature due to the…
A \emph{monopole liquid} is a magnetic charge-disordered spin system defined over an Ising pyrochlore lattice, with one single topological charge or \emph{monopole} in each tetrahedron. We define a simple model Hamiltonian for this system…
Neutron scattering is a powerful tool to study magnetic structures and dynamics, benefiting from a precisely established theoretical framework. The neutron dipole moment interacts with electrons in materials via their magnetic field, which…
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 present a proposal for applying nanoscale magnetometry to the search for magnetic monopoles in the spin ice materials holmium and dysprosium titanate. Employing Monte Carlo simulations of the dipolar spin ice model, we find that when…
The Coulomb phase, with its dipolar correlations and pinch-point-scattering patterns, is central to discussions of geometrically frustrated systems, from water ice to binary and mixed-valence alloys, as well as numerous examples of…
The spin ice materials Ho$_{2}$Ti$_{2}$O$_{7}$ and Dy$_{2}$Ti$_{2}$O$_{7}$ are by now perhaps the best-studied classical frustrated magnets. A crucial step towards the understanding of their low temperature behaviour -- both regarding their…
At low temperatures, spin ice is populated by a finite density of magnetic monopoles-pointlike topological defects with a mutual magnetic Coulomb interaction. We discuss the properties of the resulting magnetic Coulomb liquid in the…
We study the low-temperature behaviour of spin ice when uniaxial pressure induces a tetragonal distortion. There is a phase transition between a Coulomb liquid and a fully magnetised phase. Unusually, it combines features of discontinuous…
A theory of neutron scattering by magnetic materials is reviewed with emphasis on the use of electronic multipoles that have universal appeal, because they are amenable to calculation and appear in theories of many other experimental…
Dunsiger and co-workers have criticised our paper on magnetic monopole dynamics spin ice [S. T. Bramwell et al., Nature, 461 956 (2009)]. We consider their criticisms and results but show that these do not warrant any revision of our…
Spin ice in a magnetic field in the [111] direction displays two magnetization plateaux, one at saturation and an intermediate one with finite entropy. We study the crossovers between the different regimes from a point of view of…
We consider the effect of adding quantum dynamics to a classical topological spin liquid, with particular view to how best to detect its presence in experiment. For the Coulomb phase of spin ice, we find quantum effects to be most visible…
The study of magnetic correlations in dipolar-coupled nanomagnet systems with synchrotron x-ray scattering provides a means to uncover emergent phenomena and exotic phases, in particular in systems with thermally active magnetic moments.…
Electrically charged particles, such as the electron, are ubiquitous. By contrast, no elementary particles with a net magnetic charge have ever been observed, despite intensive and prolonged searches. We pursue an alternative strategy,…
The possibilities of combining several degrees of freedom inside a unique material have recently been highlighted in their dynamics and proposed as information carriers in quantum devices where their cross-manipulation by external…