Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain
the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in
Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles
and JavaScript.
Small metal-free organic molecules on an epitaxial graphene monolayer are shown to receive a local magnetic moment from the substrate. This magnetic moment survives when many molecules combine to form a layer, with some indication of long-range ferromagnetic order.
Model magnetic systems known as artificial spin ices have almost always been found in frozen, athermal states. But an artificial spin ice that is designed to be thermally active has now been imaged as it explores its frustrated energy landscape.
Usually a laser consists of a light-amplifying medium nested between two mirrors. A mirrorless laser that operates by forcing the light to take a long, random path through the gain medium has now been demonstrated.
Low-temperature experiments on spin ice indicate that entropy plateaus at a value close to that estimated for water ice — a result at odds with the third law of thermodynamics. New measurements below 500 mK are consistent with the idea that spin ice finds a way to lose this residual entropy.
Surface-plasmon polaritons are hybrid particles that result from strong coupling between light and collective electron motion on the surface of a metal. This Review presents an overview of the quantum properties of surface plasmons, their role in controlling light–matter interactions at the quantum level and potential applications.
Quantum coherence has been extensively investigated in quantum optics, but less is known about its properties in massive particles. The higher-order many-body correlation functions have now been measured in an atom optics experiment, validating Wick’s theorem.
Two indistinguishable single photons that simultaneously enter a beam splitter will always leave together, and this Hong–Ou–Mandel effect is now observed with microwave photons for the first time. Coherence between the beam-splitter output arms is demonstrated, enabling two-mode entanglement, which is useful for quantum communication processing at microwave frequencies.
Different probes have found different superconducting pairing states in different iron-based high-temperature superconductors. Now transport measurements suggest that pressure drives the superconducting state in KFe2As2 from d-wave to s-wave.
Early specific-heat measurements of the archetypal spin ice Dy2Ti2O7 showed a residual entropy at low temperatures similar to that found in water ice. A technique exploiting slow thermal equilibration now reveals an absence of this entropy—calling into question the nature of Dy2Ti2O7 at low temperatures.
Random lasing, where light is amplified through multiple scattering in a gain medium, could occur naturally in astrophysical environments. Experimental evidence for random lasing in a cloud of cold atoms may lead to a better understanding of these astrophysical lasers.
Dynamical maps are well known in the context of classical nonlinear dynamics and chaos theory. A trapped-ion quantum simulator can be used to study the generalized version of dynamical maps for many-body dissipative quantum systems.
Despite its impressive mechanical and electronic properties, graphene’s magnetic characteristics are poor. However, adsorbed organic molecules can give the material magnetic functionality, and the magnetic moment remains when the molecules combine to form dimers or even a continuous monolayer.
Artificial spin-ice promises a means of probing dynamics in frustrated systems, but samples typically only shift between low-lying energy states under an external field. Exploring the energy landscape is now possible, through exquisite control over the thermal fluctuations of mesoscopic magnetic dipoles.
