2016 Nobel Prize in Physics

British-born theorists recognized for work on topological phases.

An old branch of mathematics has paved the way for discovering new phases of matter.

A new class of materials is poised to take condensed-matter physics by storm. Geoff Brumfiel looks at what is making topological insulators all the rage.

Some experts think that a quantum computation could be plaited like a skein of string. And now they may have found the sorts of string they need, finds Liesbeth Venema.

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

Using optical lattices to trap ultracold atoms provides a powerful platform for probing topological phases, analogues to those found in condensed matter. But as these systems are highly tunable, they could be used to engineer even more exotic phases.

The Haldane model, which predicts complex topological states of matter, has been implemented by placing ultracold atoms in a tunable optical lattice that was deformed and shaken.

First-principles calculations predict that Bi₂Se₃, Bi₂Te₃ and Sb₂Te₃ are topological insulators—three-dimensional semiconductors with unusual surface states generated by spin–orbit coupling—whose surface states are described by a single gapless Dirac cone. The calculations further predict that Bi₂Se₃ has a non-trivial energy gap larger than the energy scale k_BT at room temperature.

Three-dimensional Dirac semimetals are a recently discovered state of condensed matter considered as the 3D analogue of graphene. Here, Yang et al. propose a general framework to classify stable 3D Dirac semimetals in systems with time-reversal, inversion and uniaxial rotational symmetries.

When doped with copper, the topological insulator Bi₂Se₃ becomes superconducting. But for new physics and applications the search is not for just any superconductor; the material must retain its topological character. And indeed that is the case with doped Bi₂Se₃.

The mathematical connection between isostatic lattices—which are relevant for granular matter, glasses and other ‘soft’ systems—and topological quantum matter is as deep as it is unexpected.

The fractional quantum Hall effect occurs when electrons move in Landau levels. In this study, using a theoretical flat-band lattice model, the fractional quantum Hall effect is observed in the presence of repulsive interactions when the band is one third full and in the absence of Landau levels.

The fabrication of oxide thin-film heterostructures has improved considerably over the past few years. The first demonstration of the fractional quantum Hall effect in an oxide now attests to the potential of these compounds to rival conventional semiconductors.

Non-trivial topological phases can allow for one-way spin-polarized transport along the interfaces of topological insulators but they are relatively uncommon in the condensed state of matter. By arranging judiciously designed metamaterials into two-dimensional superlattices, a photonic topological insulator has now been demonstrated theoretically, enabling unidirectional spin-polarized photon propagation without the application of external magnetic fields or breaking of time-reversal symmetry.

Multi-terminal superconducting Josephson junctions are used to induce topologically protected transitions between gapless and gapped states, showing the potential for creating artificial topological materials.