Reviews & Analysis

Spin coherence of valence holes in semiconductor quantum-dots is governed by interactions with the nuclear spins of the dot lattice. Experiments and theory have revealed an important new ingredient that determines the strength and sign of this coupling.

A technique for detecting the presence of a photon without destroying the quantum message it carries could ultimately lead to a loophole-free test of quantum non-locality.

Could biological systems have evolved to find the optimal quantum solutions to the problems thrown at them by nature? This Review presents an overview of the possible quantum effects seen in photosynthesis, avian magnetoreception and several other biological systems.

Magnets built of molecular rings of magnetic ions are fundamental model systems for studying the complex correlations and dynamics of quantum spins at the atomic scale. A new generation of neutron spectrometers can reveal complete four-dimensional maps of the spin correlations in spin rings.

The discovery of charge-density-wave order in the high-temperature superconductor YBa₂Cu₃O_6+y places charge order centre stage with superconductivity, suggesting that they are intertwined rather than competing.

Liquid water expands when heated — or cooled — away from a particular temperature that increases when the fluid is stretched. Experiments on water under extreme tension now enable tracking of this distinctive behaviour well into the negative-pressure domain.

Quantum spin liquids have long eluded detection, despite nearly forty years of investigation. Now, a topological property unique to the quantum-spin-liquid state has emerged as a viable method of detection.

The idea of monopoles in spin ice has enjoyed much success in the intermediate temperature regime. Low-temperature measurements now point to the importance of surfaces and impurities in monopole dynamics, in providing extrinsic resistance for monopole currents.

Hyper-transport — an increase in diffusion beyond the ballistic-transport regime — is observed in an optical system.

A technique for protecting out-of-equilibrium nuclear spin states from thermalization while offering a route to converting them into observable NMR signal is an important contribution to a field that welcomes every bit of extra signal.

A superconducting device that exhibits voltage steps twice as large as expected could harbour Majorana fermions.

Topological insulators have an electronic structure that supports topologically protected surface states. Now it seems that crystal symmetry can likewise generate protected states in a new class of materials known as 'topological crystalline insulators'.

Answers to fundamental questions about the nature of non-locality shed new light onto the spacetime structure and the role of causality in quantum theory, topics that have traditionally been studied within the quantum gravity community.

An investigation of Coulomb drag in graphene integrated into a stacked heterostructure unveils unexpected electron–hole symmetry-breaking in two-dimensional electronic crystals.