Letters in 2018

The state of a superconducting circuit qubit governs the photonic heat flow through an integrated assembly, constituting a quantum heat valve that provides a testbed for exploring quantum thermodynamics in a circuit quantum electrodynamics setting.

Transport measurements performed on MoGe superconducting nanowires reveal a quantitative agreement with quantum critical behaviour driven by a pair-breaking mechanism.

The authors theoretically investigate a novel form of a Doppler effect in homogeneous systems with positive refractive index that occurs under certain conditions. It is suggested that this Doppler effect can be experimentally separated from other Doppler effects by using polaritons such as those found in graphene.

Optoelectronic experiments show that a monolayer of WTe₂ is a material that simultaneously has topological electronic states and electron wavefunctions with a dipole in their Berry curvature.

Laser cooling of optically trapped diatomic molecules CaF to sub-Doppler temperatures has been achieved. The technique provides an alternative approach towards the production of ultracold polar molecules.

By coupling photons in two distinguishable modes to separate transitions of a single atom, strong correlations between photons are created. The technique makes all-optical switching and sensing possible at the single-photon level.

Spins are transmitted over a distance of 5 μm through a piece of antiferromagnetic graphene. This shows that graphene can be a platform to explore the fundamental physics of spin transport in antiferromagnets for application in spintronics.

Magnetically tunable scattering resonances between strontium and rubidium atoms are observed in an ultracold experiment, opening the door to exploring quantum many-body physics with new designed molecules.

A superlattice consisting of SrIrO₃ and SrTiO₃ is shown to display a giant response to sub-tesla external magnetic fields—a direct consequence of its antiferromagnetic nature.

Origami-inspired metamaterial design gives rise to structures with kinematic properties dictated by the topology of their configuration space. The approach allows for well-defined metamaterial properties even in the presence of unpredictable forces.

Long-range ferromagnetic order in co-doped topological insulator thin films and their typical ferromagnetic domain behaviour is directly evidenced by low-temperature magnetic force microscopy.

An off-resonant radiofrequency modulation scheme applied to a strongly interacting superfluid Fermi gas reveals the presence of a Higgs mode — an oscillation of the amplitude of the superconducting order parameter.

A phase of strongly interacting electrons that has a spontaneous dipole moment is seen for the first time using an approach that images the electron's wavefunction through interference at an impurity.

A neutron scattering study of an Ising-like quasi-one-dimensional antiferromagnet, BaCo₂V₂O₈, reveals a topological quantum phase transition when it is subjected to a transverse magnetic field.

α-RuCl₃, a promising candidate to realize the Kitaev model, has attracted great interest recently. Two types of fractional excitation—gauge fluxes and Majorana fermions—are observed, which contribute to the spin excitation gap in different ways.

A new type of exciton is observed in transition-metal dichalcogenide heterobilayers that is indirect in both real space and momentum space. It consists of a paired electron in MoS₂ at the K point and hole spread across MoS₂ and WSe₂ at the Γ point.

A detailed and systematic neutron scattering study of rare-earth pyrochlore magnet Pr₂Hf₂O₇ provides evidence for a quantum spin ice state, and emergent lattice quantum electrodynamics consistent with theoretical predictions.

Sending quantum states as shaped microwave photonic wavepackets realizes on-demand, high-fidelity quantum state transfer and entanglement between two superconducting cavity quantum memories.

Antiparallel streams of nematically oriented cells arise in both embryonic development and cancer. In vitro experiments and a hydrodynamic active gel theory suggest that these cells are subject to a transition that is driven by their activity.

Light fields of energy comparable to the Coloumb field that binds valence electrons in atoms generate states where nearly free electrons oscillate in the laser field. These are now shown to exist in rare gases, acting as gain for laser filamentation.