Volume 11 Issue 2, February 2015

Nature Physics will soon offer the option of double-blind peer review, for which authors and referees are anonymous.

Recent ultracold atom experiments reveal the wavefunction dynamics in the quantum Hall regime.

The Higgs mechanism is normally associated with high energy physics, but its roots lie in superconductivity. And now there is evidence for a Higgs mode in disordered superconductors near the superconductor–insulator transition.

The valley index of an electron is a magnetic moment that can be initialized optically and probed electrically. Now, experiments reveal how magnetic fields can break the degeneracy for states with different valley indices.

Even simple periodic mechanical lattices can exhibit exotic topologically protected modes. Incorporating defects into the mix makes things more interesting — revealing modes whose characteristics depend on properties of both the lattice and the defect.

The Rosetta orbiter following Comet 67P has captured not only the public imagination but also actual dust grains from the comet's nucleus, revealing their composition, morphology and strength.

The successful formation of self-generated magnetic fields in the lab using large-scale, high-power lasers opens the door to a better understanding of some of the most extreme astrophysical processes taking place in the Universe.

The monopole picture for spin ice offers a natural description of a confounding class of materials. A 2009 paper in Nature Physics applied it to study the dynamical properties of these systems — sparking intense experimental and theoretical efforts in the years that followed.

Our framework for understanding non-equilibrium behaviour is yet to match the simplicity and power of equilibrium statistical physics. But recent theoretical and experimental advances reveal key principles that unify seemingly unrelated topics.

Fluctuation theorems go beyond the linear response regime to describe systems far from equilibrium. But what happens to these theorems when we enter the quantum realm? The answers, it seems, are now coming thick and fast.

Equilibrium physics is ill-equipped to explain all of life’s subtleties, largely because living systems are out of equilibrium. Attempts to overcome this problem have given rise to a lively field of research—and some surprising biological findings.

Experiments probing non-equilibrium processes have so far been tailored largely to classical systems. The endeavour to extend our understanding into the quantum realm is finding traction in studies of electronic circuits at sub-kelvin temperatures.

Statistical mechanics is adept at describing the equilibria of quantum many-body systems. But drive these systems out of equilibrium, and the physics is far from clear. Recent advances have broken new ground in probing these equilibration processes.

The task of integrating information into the framework of thermodynamics dates back to Maxwell and his infamous demon. Recent advances have made these ideas rigorous—and brought them into the laboratory.

Charge carriers in transition metal dichalcogenides have an extra degree of freedom known as valley pseudospin, which is associated with the shape of the energy bands. Experiments show that this pseudospin can be manipulated using magnetic fields.

Charge carriers in transition metal dichalcogenides have an extra degree of freedom known as valley pseudospin, which is associated with the shape of the energy bands. Experiments show that this pseudospin can be manipulated using magnetic fields.

Mechanical metamaterials are artificial structures whose properties originate from their geometry. In such structures, it is now shown that topological modes can exist that are robust against a range of structural deformations.

To gain insight into the properties of quantum matter, a superatom—an ensemble of strongly interacting atoms in the Rydberg blockade regime—is created and characterized by precisely controlling the density and Rydberg excitations.

Chern numbers characterize the quantum Hall effect conductance—non-zero values are associated with topological phases. Previously only spotted in electronic systems, they have now been measured in ultracold atoms subject to artificial gauge fields.

The quantum mechanical concept of ‘steering’ refers to the feasibility of one system to nonlocally affect, or steer, another system’s states through local measurements. Multipartite steering is now demonstrated in a programmable optical network.

Astrophysical processes are often driven by collisionless plasma shock waves. The Weibel instability, a possible mechanism for developing such shocks, has now been generated in a laboratory set-up with laser-generated plasmas.

The mechanism holding Cooper pairs together in iron-based superconductors is highly debated. Finding the fingerprint of the pairing mechanism would be a leap forward.

Topological charges form readily at defects in liquid crystals, but controlling them is a formidable task. An innovative approach pins defects to a microfibre, enabling controlled creation and manipulation of topological charges.

The Higgs mechanism is best known for generating mass for subatomic particles. Less well-known is that the idea originated in the study of superconductivity, and can be tested in the laboratory.

The Jarzynski equality, relating non-equilibrium processes to free-energy differences between equilibrium states, has been verified in a number of classical systems. An ion-trap experiment now succeeds in demonstrating its quantum counterpart.

It's no game.

Efforts to probe the physics of systems removed from equilibrium date back to Maxwell himself. But recent progress has renewed interest in the endeavour — a trend highlighted by this Insight, collecting key advances from across the research spectrum.