Volume 16 Issue 3, March 2020

In 1985, experiments revealed the quantum behaviour of a macroscopic degree of freedom: the phase difference across a Josephson junction. The authors recount the history of this milestone for the development of superconducting quantum circuits.

Speed is of the essence when it comes to signal processing, but electronic switching times have reached a limit. Optically controlled tunnel currents across a nanoscale plasmonic gap could considerably accelerate future nanoelectronic devices.

This article puts in perspective the relationship between cavity and circuit quantum electrodynamics, two related approaches for studying the fundamental quantum interaction between light and matter.

The introduction of concepts from cavity quantum electrodynamics to superconducting circuits yielded circuit quantum electrodynamics, a platform eminently suitable to quantum information processing and for the exploration of novel regimes in quantum optics.

Hybrid quantum systems combine heterogeneous physical systems for the implementation of new functionalities at the quantum level. This article reviews recent research on the creation of hybrid quantum systems within the circuit quantum electrodynamics framework.

This Review Article surveys the physics of many-body quantum states formed by microwave photons in circuit quantum electrodynamics environments.

Experiments demonstrate quantum phase sensing with a four-mode entangled state, reaching a measurement precision that is beyond what can be achieved by separate individual probes.

The authors develop a high-spatial-resolution photoemission technique to show variation of the energy of the Dirac point of approximately 50 meV. They also find an interplay between bulk and surface states.

A combined ARPES and DFT study of Ru- and Rh-substituted samples of Sr₂IrO₄ reveals a collapse of its correlated insulating phase that is controlled by spin–orbit coupling.

Applying pressure to a cuprate reveals that the strange metal phase has a two-dimensional character, as shown by emerging Berezinskii–Kosterlitz–Thouless behaviour.

Non-equilibrium Bose–Einstein condensation of exciton polaritons in chains of lead halide perovskite pillars can occur at room temperature. These condensates have long spatial coherence.

In natural materials, defects determine many properties. In spin-analogue mechanical metamaterials, deterministically inserted topological defects enable the design of complex deformation and stress distributions.

The motor protein dynein is associated with microtubule force generation in the cell; how it interacts with cytoskeletal fluctuations is still an open question. Here the authors show that dynein can harness these fluctuations to generate power and move faster towards the minus-end of microtubules.

Magnetic reconnection in the near-Earth magnetotail is observed to power a space storm, although suppression of magnetic reconnection caused by the Earth’s magnetic dipole was expected close to Earth.

The variational quantum unsampling protocol provides a way to realize verification and inference of near-term quantum circuit outputs. This protocol is then experimentally verified on a quantum photonic processor.

Following an impulsive laser excitation of a single molecule, a dispersed vibrational wave-packet is partially rephased by a second pulse, and a wave-packet echo is observed. This wave-packet echo probes ultrafast intramolecular processes in the isolated molecule.

The optical analogue of electromagnetically induced transparency and absorption can be modulated by chiral optical states at an exceptional point, which is shown in a system of indirectly coupled microresonators.

Single-cycle interferometric autocorrelation measurements of electrons tunnelling across the gap of a plasmonic bowtie antenna and quantitative models provide insight into the physical interactions that drive the electron transfer.

Transport measurements show that nematic fluctuations near a phase transition increase the temperature at which superconductivity occurs by a factor of nearly six. This happens in a non-magnetic nickel-based compound.

An experiment with three alternating-current generators demonstrates converse symmetry breaking—a phenomenon whereby the system achieves frequency synchronization when its component systems are tuned asymmetrically.

A detailed theoretical and experimental investigation of homogeneous cell tissues finds that they can undergo spontaneous spatial symmetry breaking through a purely electrophysiological mechanism.

Philip Lössl tells of mass spectrometry’s struggles to come to terms with terminology.