Articles in 2008

Analysis of the best available data on the behaviour of a large number of glass-forming organic liquids suggests that the widespread belief that a glass ceases to flow below its transition temperature could be wrong.

The experimental demonstration of a continuous and irreversible transfer of cold atoms from a ‘source mode’ to a ‘laser mode’ represents a step closer to a fully continuous atom laser.

A class of quantum-cryptographic protocols is proposed that involves back-and-forth communication between two parties. The approach is shown to provide enhanced security and should tolerate higher levels of noise and loss than conventional ‘one-way’ protocols.

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.

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 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.

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.

A technique that uses the rotating electric-field vector of a circularly polarized laser pulse as a ‘clock’ provides a fresh approach to measuring electron dynamics with attosecond time resolution.

Measurements of the position of a nanoscale beam using a microwave cavity detector represents a promising step towards being able to measure displacements at the quantum limit.

Nanoscale beams are one platform for exploring quantum-mechanical phenomena in ever-larger systems. The collective motion of a macroscopic ensemble of ultracold atoms confined in an optical cavity is established as an alternative approach.

When a thermodynamic system is changed sufficiently slowly, entropy is generally conserved and the process is adiabatic, and therefore reversible. However, this adiabaticity does not seem to hold for low-dimensional systems with a high-density of low-energy states.

Solitons are encountered in a wide range of nonlinear systems, from water channels to optical fibres. They have also been observed in Bose–Einstein condensates, but only now have such ‘ultracold solitons’ been made to live long enough for their dynamical properties to be studied in detail.

Superfluid ³He is a quantum condensate in which the He atoms are paired in an unconventional way. Yet despite extensive research on the collective modes of superfluid ³He, one mode has remained undiscovered, until now.

The analysis of the interference fringes generated by initially independent one-dimensional Bose condensates reveals contributions of both quantum noise and thermal noise, advancing our fundamental understanding of quantum states in interacting many-body systems.

A proposal describes how to detect topologically ordered states of ultracold matter in an optical lattice, and shows how these exotic states, which strongly correlated quantum systems can exhibit, could be harnessed for practical applications, such as robust quantum computation.

Laser-driven resolved sideband cooling of the resonant vibrational mode of a toroidal microcavity represents another step towards reaching the quantum ground state.

There are two major theories regarding the normal state of a high-temperature superconductor: that the ‘pseudogap’ state is either a disordered superconductor or a distinct and competing phase. But could it be both?

In conventional superconductors, the critical temperature goes to zero as the density of charge carriers falls due to increased scattering. But in high-temperature superconductors, the scattering rate as a function of charge carriers was unknown, until now.

Random collisions between particles usually generate disorder in a system. But under certain conditions, particles in suspended in a liquid subjected to periodic shear forces can collide in a way that leads to fewer subsequent collisions and less disorder.

The one-dimensional case of the so-called ‘Wigner crystal’ phase of electrons—long predicted but previously only seen in two-dimensional electron systems—has finally been observed, in a carbon nanotube.