Volume 5 Issue 3, March 2009

Science can explain many things in the natural world. Although the laws of gravity, the origin of galaxies and the Universe are commonly accepted, the theory of evolution is still questioned by some. There are clear reasons for why that is, and why it need not be so.

The modern evolutionary synthesis, which marries Darwin's theory of natural selection with Mendel's genetics, was developed around the same time as quantum mechanics. Is there any connection between the two?

In many ways, semiconductor quantum dots behave like natural atoms, but it has proved difficult to manipulate them using resonant laser light. That problem is now overcome.

Shot noise measurements in carbon nanotube quantum dots show many-body effects related to exotic Kondo models with both spin and orbital angular momentum, paving the way for studies on a rich class of strongly correlated transport phenomena.

A new theory for dark matter has the power to explain several experimental results simultaneously, even those seemingly at odds with each other.

Analogues of the resistors, capacitors and diodes of an electronic circuit could eliminate the need for bulky external pumps to control the flow of liquids in a microfluidic circuit.

Quantum Darwinism describes the proliferation, in the environment, of multiple records of selected states of a quantum system — an approach that has resulted in considerable progress towards a solution of the quantum measurement problem.

Quantum superpositions of coherent light waves offer several advantages for quantum-information processing compared to single photons. A novel scheme for generating these so-called Schrödinger-cat states circumvents problems arising from their fragility, which has been a key obstacle towards applications.

Two intriguing shapes that appear in Bose–Einstein condensates are vortex rings and solitons. Experiments now suggest that there can be periodic oscillations between these qualitatively different structures.

Two experiments observe the so-called ‘Mollow triplet’ in the emission spectrum of a quantum dot—originating from resonantly driving a dot transition—and demonstrate the potential of these systems to act as single-photon sources and as a readout modality for electron-spin states.

Two experiments observe the so-called Mollow triplet in the emission spectrum of a quantum dot—originating from resonantly driving a dot transition—and demonstrate the potential of these systems to act as single-photon sources, and as a readout modality for electron-spin states.

Sensitive measurements of fluctuations in the current through carbon-nanotube-based quantum dots provide insight into the many-body physics of such systems.

A variant on Fourier-transform scanning tunnelling spectroscopy enables spatial variations in the Fermi surface of bismuth-based cuprate superconductors to be probed. This technique reveals that these variations take place over nanometre distances.

Although spin fluctuations are believed to have an important role in the mechanism responsible for high-temperature superconductivity, it has been unclear whether the strength of their coupling with fermionic quasiparticles is sufficiently strong. Systematic analysis of angle-resolved photoemission and neutron spectra suggests it is.

The observation of oscillations in the conductance characteristics of narrow graphene p–n-junctions confirms their ability to collimate ballistic carriers. Moreover, the phase of these oscillations at low magnetic field suggests the occurrence of the perfect transmission of carriers normal to the junction as a direct result of the Klein effect.

The observation of a trimer resonance in an ultracold mixture of caesium atoms and dimers confirms one of the key predictions of three-body physics in the limit of resonant two-body interactions, with possible implications for understanding few-body states in nuclear matter.

Frequency-specific components that passively control the flow in a channel in an analogous manner to that of the resistors, capacitors and diodes of an electronic circuit could eliminate the need to exert active control in microfluidic circuits with bulky external pumps.

Darwin and physics? The relevance of Darwin's ideas in physics, the wider context of Darwin's legacy and the controversy that rumbles on are explored in a special collection of articles marking the anniversary of the theory of evolution.