Research articles

Disproving hidden variables is a fundamental test for the validity of quantum mechanics and its nonlocal features. In this work, the authors consider a refined model where the spin magnitudes are conserved. In this way they can show a violation of the hidden variable model by a wider class of quantum states.

The origin of the superconductivity in iron-based superconductors remains elusive and whether a mechanism which describes all members can be found is under constant study. Using Raman spectroscopy the authors investigate magnetic ordering in FeSe, and further demonstrate that its properties are distinct among the iron-based superconductors.

Artificial spin ices are nanoscale frustrated lattices that mimic many of the properties seen in bulk frustrated materials. In this study, a new method is used to produce a 3D nanostructured frustrated lattice. Magnetic microscopy and simulations are then used to elucidate its underlying spin texture.

The successful isolation of a single layer of graphene has led to great interest in finding other 2D materials with similar electronic characteristics with additional spin-dependent phenomena. In this work, a 2D allotrope of Sn is grown on an Au(111) surface and shown through angle-resolved photoemission spectroscopy to have a linear band dispersion at the zone center and anti-parallel spin polarization.

The Pauli exclusion principle can be formulated in a generalized form where additional constraints are imposed to the orbital degrees of freedom of electrons. In this work these constraints are experimentally verified on a five qubit quantum computer with an error of one part in one quintillion.

An understanding of charge dynamics and direct observations of charge generation, transfer and recombination is important to help develop and apply various materials for electronic devices. The authors develop a time-resolved electrostatic force microscopy technique to visually observe charge migration on the nanoscale at a sub-microsecond timeframe.

The properties of strongly correlated materials have been successfully studied via ultrafast dynamics methods. The authors present combined experimental and theoretical results of photo-excitation of LaCoO₃ to probe the mechanisms at play behind the semiconductor-to-metal transition at high temperature.

The security of communications networks is a fundamental challenge of the current era, particularly with the move towards quantum communications. The authors perform joint transmission of quantum key distribution and up to 100 classical communication channels in the same fiber and report an average secret key rate of 27.2 kbit/s over a 24 h operation period where the classical data rate amounted to 18.3 Tbit/s.

Magnetorotational Instability (MRI) has long been considered a possible mechanism to transport angular momentum allowing fast accretion in astrophysical objects, but its standard form with a vertical magnetic field has never been experimentally verified. The authors present an experimental demonstration of a spring-mass analogue of the standard MRI using water as working fluid and a spring to mimic the action of magnetic fields.

Silicon carbide is a wide-bandgap semiconductor with outstanding properties for efficient high-power electronic devices whose ultimate potential could not yet be exploited due to the presence of interface traps. The authors develop an experimentally less demanding analysis method that takes such defects into account when determining device parameters.

Electron or hole doping of cuprates is a well-known method to create a superconducting system, but its charge dynamics remains elusive. Here the authors theoretically demonstrate that the high-energy charge fluctuations are understood in terms of acoustic-like plasmons and are universal for both the hole and electron doped cuprates.

The search for experimental evidence of Majorana modes is an area of intense research in condensed matter and quantum physics and uncovering clear evidence is complicated. The authors investigate the impact of Joule heating which can influence the analysis of experimental features related to Majorana bound states in topological Josephson junctions.

Scannerless time of flight three-dimensional devices can produce high-quality images from the ground or in space and provide information on light detection and ranging. The authors design and demonstrate a downscaled subpixel 3D laser imaging device which uses pulse-encoded illumination to encode the pixels.

Organic light emitting diodes are an important component of current technologies, and methods to enhance their efficiencies are under constant investigation. The authors demonstrate that disorder near the surface of these systems is responsible for the energy alignment between their host and dopant molecules and hence their overall efficiency.