Volume 4 Issue 8, August 2008

A way to generate and control spin currents without magnetic fields or magnetic materials may be possible using dissipative quantum ratchets in the presence of spin–orbit coupling.

Inspired by ideas and techniques for cooling atomic gases, an experiment demonstrates how the temperature of micrometre-scale electronic devices can be lowered using solid-state quantum circuits.

The ability to change the degree of hybridization of a donor electron between the coulombic potential of its donor atom and that of a nearby quantum well in a silicon transistor has now been achieved. This is a promising step in the development of atomic-scale quantum control.

When is a condensate really a condensate? Calculations reveal that a 'peak on a peak' structure should be considered the true signature of the emergence of a Bose condensate in a Bose–Hubbard optical lattice.

The ability to control the velocity of molecules using time-varying electrical and magnetic fields has led to a renewed interest in molecular beams. This article reviews the technology of these decelerators and discusses applications.

A long-sought ytterbium-based heavy-fermion superconductor—a hole analogue of the cerium-based systems—has been found. Moreover, there is evidence for a quantum critical point at ambient conditions and without chemical doping.

The pseudogap state in the high-temperature superconductors may be either a precursor state to superconductivity or a competing state. A direct probe of the Cooper pairs can address this conundrum.

A superconducting qubit—a mesoscopic structure that behaves like a quantum two-level system—has been used to change the temperature of a resonant circuit, in close analogy to the so-called Sisyphus cooling and amplification protocols used in laser cooling of atoms.

Recognizing a superfluid when we see one may be more difficult than we originally thought. Simulations suggest that the sharp peaks associated with superfluidity in ultracold atoms do not provide a unique signature after all.

A rich internal structure and long-range interactions between them make molecules with non-vanishing dipole moments interesting for many applications. An experiment demonstrating the efficient transfer of loosely bound heteronuclear molecules into more deeply bound energy levels indicates a route towards producing dense ensembles of cold polar molecules.

Scanning tunnelling spectra of a graphene field-effect transistor reveal an unexpected tenfold increase in conductance as a result of phonon-mediated inelastic tunnelling.

Emission coherence is crucial to the potential of future X-ray sources based on high-order harmonic generation from laser-driven plasmas. Contrary to expectations, coherent emission is possible, but only if the pulses driving it are temporally sharp.

The use of a quantum point contact to detect the thermal motion of a nearby microcantilever demonstrates a potentially useful tool in the quest to push the sensitivity of displacement sensors to the ultimate quantum limit.

Unconventional superconductors often host two or more competing states at low temperatures. Line defects seemingly have a role in the relative stability of coexisting density waves that oscillate in space.

The Kondo problem—dealing with localized magnetic impurities embedded in a sea of conduction electrons—can be treated on an equal footing with superconductivity for a large system of interacting electrons.

Similar to electrons passed through a double-slit apparatus, photoelectrons emitted coherently from both atoms of a diatomic molecule can exhibit interference patterns. But when coherence between the two atoms is lost, effects are shown to come into play that are unique to the ‘molecular double-slit’ experiment.

The ability to change the degree of hybridization of a donor electron state between the coulombic potential of its donor atom and that of a nearby quantum well in a silicon transistor has now been achieved. This is a promising step in the development of atomic-scale quantum control.

A blast from the past.