Articles in 2011

Monolayer graphene is a semimetal with no bandgap, and bilayer graphene is a semiconductor with a tunable gap. A trio of studies now shows that trilayer graphene can be either, depending on how its layers are stacked — behaviour that could support exotic new electronic states.

Manipulating the electrons trapped in quantum-dot pairs is seen as one possible route to quantum computation. This idea is now extended to three quantum dots, enabling a whole host of extended functionality.

Manipulating the electrons trapped in quantum-dot pairs is one possible route to quantum computation. Translating this idea to three quantum dots would enable a whole host of extended functionality. Researchers now generate and manipulate coherent superpositions of quantum states using the spins across three electrical-gate-defined dots.

The discovery that potassium-doped iron selenide undergoes phase separation into a defect-free superconducting phase and an iron-vacancy-ordered insulating phase resolves many questions about the unusual behaviour of this iron-based superconductor.

Experimental progress has made it possible to load fermionic atoms into higher orbital bands. Such systems provide a platform for studying quantum states of matter that have no prior analogues in solid-state materials. This theoretical study predicts a semimetallic topological state in these systems, which can be turned into a topological insulating phase.

Laser-driven proton accelerators could enable more effective cancer treatment, but to fulfil this function proton beams with a higher energy and narrower energy spread will need to be produced. Discovery of a laser–plasma acceleration mechanism that generates 20 MeV proton beams with a 1% spread is a promising step.

The controlled creation of one-dimensional conductive channels at the cores of topological defects in the multiferroic material BiFeO₃ demonstrates that such defects can drive metal–insulator phase transitions, and might provide a route towards high-density information storage.

Photoelectron spectroscopy is an invaluable tool for better understanding the energy levels of molecules. However, many levels remain hidden because of transition selection rules or a high density of states. Using X-rays to excite core–shell electrons and monitoring their Auger decay enables the extraction of previously hidden molecular-potential curves.

Increasingly, scientists are expected to go beyond the traditional scientific paper to explain their research to a non-specialist readership. We offer some tips on writing popular science for a general audience.