Magnetic monopoles, proposed as elementary particles that act isolated magnetic south and north poles, have long attracted research interest analogs to electric charge. In solid-state physics, a classical analog these elusive has emerged topological excitations within pyrochlore spin ice systems. We present the first real-time imaging of emergent monopole motion in macroscopically degenerate artificial system consisting thermally activated Ising-type nanomagnets lithographically arranged...

Abstract Electric charge screening is a fundamental principle governing the behaviour in variety of systems nature. Through reconfiguration local environment, Coulomb attraction between electric charges decreased, leading, for example, to creation polaron states solids or hydration shells around proteins water. Here, we directly visualize real-time and decay screened magnetic configurations two-dimensional artificial spin ice system, dipolar dice lattice. By comparing temperature dependent...

Abstract Geometrical frustration occurs when entities in a system, subject to given lattice constraints, are hindered simultaneously minimize their local interactions. In magnetism, systems incorporating geometrical fascinating, as behavior is not only hard predict, but also leads the emergence of exotic states matter. Here, we provide first look into an artificial frustrated dipolar trident lattice, where balance competing interactions between nearest-neighbor magnetic moments can be...

Widely applicable, modified Green-Kubo expressions for the local diffusion coefficient (Dl) are obtained using linear response theory. In contrast to past definitions in use, these statistical mechanical results. Molecular simulations of systems with anisotropic and an inhomogeneous density profile confirm validity Diffusion coefficients determined from different terms currents velocity correlations agree limit large systems. Furthermore, they apply arbitrarily small regions, making them...

We present a realization of highly frustrated planar triangular antiferromagnetism achieved in quasi-three-dimensional artificial spin system consisting monodomain Ising-type nanomagnets lithographically arranged onto deep-etched silicon substrate. demonstrate how the three-dimensional architecture results first direct observation long-range ordered antiferromagnetism, addition to disordered phase with short-range correlations, once competing interactions are perfectly tuned. Our work...

The potential application of artificial spin ice in magnetic nanodevices provides a strong drive to investigate different lattice geometries. Here, we combine components recently investigated ratchet with the prototypical square form geometrically frustrated system where Ising-type nanomagnets are arranged onto two-dimensional square-kite lattice. Using synchrotron-based photoemission electron microscopy, explore moment configurations achieved this geometry. Following thermal annealing,...

Anomalous transport through soft percolating host structures is dominated by passages over high mountain passes.

We introduce the stretched pentagonal spin ice and study low-energy configurations achieved after thermal annealing. Using synchrotron-based photoemission electron microscopy, we reveal highly disordered dominated by short-range order. Real-space observations that an adherence to local order, in form of a strict ice-rule obedience, acts as main factor enforcing vertex frustration hindering long-range Our results open up pathways create forms frustrated systems have seemed elusive thus far....

Confined fluids display complex behavior due to layering and local packing. Here, we disentangle these effects by confining a hard-sphere fluid the surface of cylinder, such circumference extends only over few particle diameters. We compare static structure factor pressure measured in computer simulations Percus–Yevick closure liquid state theory. A non-monotonic evolution static-structure-factor peak is observed upon variation length, similar confined between two plates. This indicates that...

The authors calculate the phase diagram of a mixture size-disperse hard spheres in confinement. Despite fact that this is prototypical model glass forming liquid, find when it confined between walls, crystals form at densities below transition point.

Using molecular dynamics simulations, we study field free relaxation from a non-uniform initial density, monitored using both density distributions and the dissipation function. When this gradient is applied to colour labelled particles, distribution decays sine curve of fundamental wavelength, which then conformally towards uniform distribution. For conformal relaxation, function found decay equilibrium monotonically, consistent with predictions theorem. system initiated more dramatic...

The complex behavior of confined fluids arising due to a competition between layering and local packing can be disentangled by considering quasi-confined liquids, where periodic boundary conditions along the confining direction restore translational invariance. This system provides means investigate interplay relevant length scales confinement order. We provide mode-coupling theory glass transition (MCT) for liquids elaborate an efficient method numerical implementation. nonergodicity...

We give a derivation of new instantaneous fluctuation relation for an arbitrary phase function which is odd under time reversal. The form this not obvious, and involves observing the system along its transient space trajectory both before after point in at fluctuations are being compared. demonstrate computationally number functions shear flow show that non-locality essential component theorem.

The authors introduce here an artificial spin system consisting of single-domain nanomagnets that are lithographically defined into trimers. Placing these trimers a triangular lattice with variable parameter allows for direct control competing interactions. result is can move between two long-range ordered phases: vortex-dominated phase and ferromagnetic phase. When interactions perfectly tuned, however, the gets caught within highly disordered short-range correlations.

Abstract Fluctuation theorems (FTs) quantify the thermodynamic reversibility of a system, and for deterministic systems they are defined in terms dissipation function. However, nonequilibrium steady state dynamics, phase space distribution is unknown, making function difficult to evaluate without extra information. As such, FTs date have required either that trajectory segment interest relatively long, or information available about entire surrounding segment. In this work, it shown simple...

We consider two different methods of calculating the relevant average for non-equilibrium partition identity (NPI), i.e. , which result in values. At best only one these will accurately correspond to what is observed. In order better understand outcomes we carry out a detailed error analysis. This analysis difficult due importance extremely rare events forming average, resulting necessity go beyond linear approximations estimates. begin by analysing fluctuation relation, and build upon this...

We carry out a theoretical analysis of the fluctuations in Johnson—Nyquist noise an RC electric circuit being driven by non-ideal constant current source. Using appropriate Langevin equation, we derive fluctuation theorem for system. This exhibits some interesting features. Firstly, average dissipation function is not necessarily just instantaneous entropy production, i.e. work done on external power source divided ambient temperature. Secondly, selection values components, transient...

In this paper we demonstrate that the weak temperature dependence of structure factor supercooled liquids, a defining feature glass transition, is consequence averaging scattering intensity either due to use an incoherent radiation source or explicit angular averaging. We show speckle at individual wavevectors, calculated from simulated former, exhibits Debye-Waller with sufficiently large represent structural order parameter capable distinguishing liquid glass. also extract intensities...

Fluctuation theorems (FTs) quantify the thermodynamic reversibility of a system, and for deterministic systems they are defined in terms dissipation function. However, nonequilibrium steady state dynamics, phase space distribution is unknown, making function difficult to evaluate without extra information. As such, FTs date have required either that trajectory segment interest relatively long, or information available about entire surrounding segment. In this work, it shown simple machine...

In this paper, we demonstrate that the weak temperature dependence of structure factor supercooled liquids, a defining feature glass transition, is consequence averaging scattering intensity due to angular averaging. We show speckle at individual wavevectors, calculated from simulated former, exhibits Debye-Waller with sufficiently large represent structural order parameter capable distinguishing liquid glass. also extract intensities quantity proportional variance local restraint, i.e.,...

Widely applicable, modified Green-Kubo expressions for the local diffusion coefficient ($D_l$) are obtained using linear response theory. In contrast to past definitions in use, these statistical mechanical results. Molecular simulations of systems with anisotropic and an inhomogeneous density profile confirm validity Diffusion coefficients determined from different terms currents velocity correlations agree limit large systems. Furthermore, they apply arbitrarily small regions, making them...