Volume 11 Issue 11, November 2015

Career opportunities are often a matter of chance, but also of a willingness to cross interdisciplinary boundaries.

The 2015 Nobel Prize in Physics has been awarded to Takaaki Kajita and Arthur B. McDonald "for the discovery of neutrino oscillations, which shows that neutrinos have mass".

A nonlinear Compton scattering experiment with X-ray photons using an X-ray free-electron laser exhibits an unexpected frequency shift — hinting at the breakdown of standard approximations.

Negative refraction can produce optical Veselago lenses with a resolution that is not diffraction-limited. Similar lenses can also be made for electrons, with negative refraction of Dirac fermions now shown in graphene.

Disorder in arrays of evanescently coupled waveguides turns out to have unexpected consequences on the photon number statistics of coherent light.

In 2009, two papers provided the first unambiguous examples of three-dimensional topological insulators — bulk insulators boasting metallic surface states with massless Dirac electrons. These now form just one of many classes of topological materials.

The internal structure of cells is organized into compartments, many of which lack a confining membrane and instead resemble viscous liquid droplets. Evidence is mounting that these compartments form via spontaneous phase transitions.

Using post-selection and electromagnetically induced transparency in a cold atomic gas it is now possible to generate a strong nonlinear interaction between two optical beams, bringing nonlinear optics into the quantum regime.

In organic semiconductors, pairs of charge-carrying spins can behave as four-level systems. It is now shown that in the regime of ultrastrong coupling, the collective behaviour of these spins gives rise to a spin-Dicke effect.

To study atomic-scale friction in a controlled environment, researchers used two trapped, laser-cooled ions in an additional optical potential. This set-up provides a better understanding of the interplay between thermal and structural lubricity.

Realizing non-trivial topological effects is challenging in acoustic systems. It is now shown that inversion symmetry breaking can be used to create acoustic analogues of the topological Haldane model.

Negative refraction has now been observed for Dirac fermions in graphene, and is used to create an electronic Veselago lens.

A theoretical study looks at the interplay between disorder and chiral symmetry in the photon statistics in a one-dimensional photonic lattice, predicting that for increased disorder coherent light becomes thermal.

Epidemics often exhibit drastic dynamics, unmatched by percolation theory—a difference that may be due to cooperation between contagions. A mechanistic model implicates network topology in regulating the efficiency of this cooperation.

The formation of vortex arrays in rotating Fermi gases is not limited to ultracold gases but may be relevant in nuclei and neutron stars, so it is important to be able to calculate their properties in a realistic fashion.

A scanning tunnelling microscopy study of monolayer FeSe on strontium titanate reveals that this intriguing system has a plain s-wave pairing symmetry.

Due to its structural simplicity, iron selenide is an attractive system for understanding the electronic mechanism for superconductivity in iron-based materials. A theoretical study now examines the influence of magnetic frustration in this system.

Nematic phases with broken crystal rotation symmetry are as ubiquitous in superconductors as they are puzzling. One model shows that frustrated magnetism alone can account for the nematicity in FeSe, which shows no measurable magnetic order.

Radiation–matter interactions can become highly nonlinear when using high-intensity X-ray free-electron lasers. Under such conditions, it is shown that nonlinear Compton scattering has an anomalous redshift, whose origin remains unclear.

Systems exhibiting slow relaxation to equilibrium are often characterized in terms of an effective temperature arising from a modified fluctuation–dissipation theorem. Single-molecule experiments provide direct evidence for the validity of this idea.

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