Research articles

Monolayer transition metal dichalcogenides are potential candidates for photonic devices but improvement in photocarrier dynamics, such as the lifetime of excitons, are first required. Using a mixture of simulation and spectroscopy the authors demonstrate that the interface between a monolayer and substrate can be used to tune exciton relaxation times in MoSe2.

Prospects for new applications in quantum simulations, spectroscopic precision measurements and very low temperature physics and chemistry have resulted in significant advances in the study of cold molecules, with their trapping for long times remaining a major challenge. The authors present an experiment in which polar molecular radicals produced by Stark deceleration are magnetically trapped for a time of order 20 s providing an improvement of up to two orders of magnitude over room temperature experiments.

The interaction between orbital angular momentum (OAM) of light and atoms can be used to store and retrieve high-dimensional information and hence has been proposed as an efficient way for quantum information networks. The authors present a scheme to store photons with a large OAM by implementing classical write and read pulses in higher OAM states.

When a material is irradiated with a high-intensity laser pulse, its surface ionization generates electrons that are accelerated close to the speed of light by the ponderomotive force of the laser light, yet how electrons’ kinetic energy scales with laser power is still unclear. The authors experimentally clarify this relation and by modelling individual electron trajectories using numerical simulations identify two acceleration mechanisms for the generation of relativistic electrons related to the dependency of the electric and magnetic fields.

To study the onset of carcinogenesis, the authors use an optogenetics approach to selectively activate with light the Src oncoprotein in cells of an epithelium with a good control in time and space. The transformed cells collectively extrude as a tridimensional aggregate from the cell sheet while remaining alive and in parallel cells of the monolayer converge toward the locus of extrusion.

Trapped ions have gained momentum as a platform for quantum computing thanks to the ability of storing qubits in stable electron states of each ions and transfer of information among the ion qubits in the trap. The authors present an experimental scheme to detect trapped 171-ytterbium ion qubits using photon statistics and superconducting nanowire single photon detectors and report a qubit detection fidelity of 99.93% within 11 microseconds.

Donor-acceptor-type conjugated polymers are expected to be a promising candidate for high mobility materials in flexible electronic devices such as thin film transistors. Using field-induced electron spin resonance spectroscopy and density functional calculations, the authors investigate the highly-efficient interdomain charge transport in two typical high-mobility donor-acceptor copolymers.

In the quantum revolution era, parallel and complementary efforts are deployed in the manipulation of quantum states and their entanglement. The authors theoretically and experimentally present a method using quantum interference in circular propagating modes of silicon microdisks to control quantum states produced by optical resonators, affording the possibility to creating higher dimensional entanglement and exotic multi-photon states.

The application of quantum dots for quantum communication is limited by the wetting layer, which is inherent to the Stranski–Krastanov growth method. Here, the authors advance this method by decoupling the quantum dot and wetting layer states, which modifies their excitonic properties.

Different subfields of physics quantify operator disagreement with different measures. The authors unite two, entropic uncertainty relations from quantum information theory and scrambling from condensed matter and high-energy physics.

Atomic Force Microscopy (AFM) provides precision imaging and force measurement offering great benefits in fields from nanotechnology to biology, but the accuracy in force measurements is still of order 10-25%. The authors present an alternative method, named Concurrent Atomic Force Spectroscopy, to study mechanical unfolding of proteins where AFM measurements are combined with Monte Carlo simulations to obtain how errors from the cantilever calibration propagate to errors in the forces measured, overcoming calibration uncertainty in relative mechanical measurements.

Defects engineering plays a central role in manipulating the electronic, optical and structure properties of materials and for device fabrication. The authors propose and experimentally verify a method to use ion beams for defect engineering of 2D materials based on a time dependent interatomic potential.

Conventional metals do no generally exhibit strong luminescence, hindering their application to nanoscale optoelectronics. Here, the authors demonstrate strong photoluminescence in metallic 2H-TaSe₂, related to a charge density wave phase, and demonstrate its suitability for future two-dimensional devices.

The discovery of magnetic phenomena in materials at the nanoscale has given rise to rich research in nanomagnetism in 3D with prospects in applications such as sensing and spintronics. The authors propose a method based on holographic vector field electron tomography to reveal the complex 3D magnetic structure of a nanowire to a 10 nm lateral resolution.

Since their discovery, Weyl fermions in topological Weyl semimetals have attracted considerable attention due to their quasi-particle analogy to fundamental particles. The authors investigate the effect of nontrivial Berry phase of Weyl topological semimetals using a p-n-p junction, and demonstrate control over the chirality-dependent electronic conductance by reducing the required magnetic field without external modification.

Inelastic collapse, whereby particles can collide an infinite number of times in finite time, has been extensively studied, and occurs under the condition of particle inertia and elasticity. The authors propose a scenario for inelastic collapse in the physics of granular materials by numerically studying the deposition of totally inelastic particles in an overdamped dynamics showing that the two conditions above are not necessary to have inelastic collapse.

Observing the dynamical Casimir effect, where two particles are generated from the vacuum, is challenging in the optical regime due to its purely-temporal nature. The authors demonstrate a dispersion-oscillating fibre system operating in the near-infrared regime and capable of resolving correlated photon pairs as an analogue to the dynamical Casimir effect.

Pt–P and Pd–P-based glass forming liquids present many similarities and yet their glass forming ability seems to differ widely. Using Synchrotron X-ray scattering experiments the authors reveal structural differences in the two families of glass-forming liquids in which both the dominant local structural motifs and their connection schemes change upon alloy composition, potentially leading to different sensitivities to annealing or cooling rate induced embrittlement.

During development, wound healing, differentiation or cancer metastasis, cells move continuously in heterogeneous environments, hence understanding how cell migration is controlled by confinement and by different substrate shapes is crucial to begin to build a first conceptual framework for cell motility. Here the authors develop a computational approach to systematically investigate the effect that a complex environment has on cell motion and speed.

Many-body physics in atomically thin materials results in intriguing phenomena. Here the authors provide a theoretical insight of the electron–phonon induced double band splitting in the ARPES spectrum in MoS₂ in terms of three well defined quasi-particles, one of which has a notably long lifetime.