Holographic codes from hyperinvariant tensor networks.

Holographic quantum-error correcting codes are models of bulk/boundary dualities such as the anti-de Sitter/conformal field theory (AdS/CFT) correspondence, where a higher-dimensional bulk geometry is associated with the code's logical degrees of freedom. Previous discrete holographic codes based on tensor networks have reproduced the general code properties expected from continuum AdS/CFT, such as complementary recovery. However, the boundary states of such tensor networks typically do not exhibit the expected correlation functions of CFT boundary states.

Conformal properties of hyperinvariant tensor networks.

Hyperinvariant tensor networks (hyMERA) were introduced as a way to combine the successes of perfect tensor networks (HaPPY) and the multiscale entanglement renormalization ansatz (MERA) in simulations of the AdS/CFT correspondence. Although this new class of tensor network shows much potential for simulating conformal field theories arising from hyperbolic bulk manifolds with quasiperiodic boundaries, many issues are unresolved. In this manuscript we analyze the challenges related to optimizing tensors in a hyMERA with respect to some quasiperiodic critical spin chain, and compare with standard approaches in MERA.

A wireless potentiostat for mobile chemical sensing and biosensing.

Wireless chemical sensors are used as analytical devices in homeland defence, home-based healthcare, food logistics and more generally for the Sensor Internet of Things (SIoT). Presented here is a battery-powered and highly portable credit-card size potentiostat that is suitable for performing mobile and wearable amperometric electrochemical measurements with seamless wireless data transfer to mobile computing devices. The mobile electrochemical analytical system has been evaluated in the laboratory with a model redox system - the reduction of hexacyanoferrate(III) - and also with commercially available enzymatic blood-glucose test-strips.

Miniaturised wireless smart tag for optical chemical analysis applications.

A novel miniaturised photometer has been developed as an ultra-portable and mobile analytical chemical instrument. The low-cost photometer presents a paradigm shift in mobile chemical sensor instrumentation because it is built around a contactless smart card format. The photometer tag is based on the radio-frequency identification (RFID) smart card system, which provides short-range wireless data and power transfer between the photometer and a proximal reader, and which allows the reader to also energise the photometer by near field electromagnetic induction.

A novel miniaturized radiofrequency potentiometer tag using ion-selective electrodes for wireless ion sensing.

Instrumental approaches to remotely and wirelessly monitoring chemical species are increasingly needed. Together with the electronic developments, efforts to optimize and validate the performance of these new devices are required. In this work, the analytical performance of a recently developed potentiometer-radiofrequency tag connected to ion-selective electrodes is evaluated.

Sensors in neonatal monitoring: current practice and future trends.

Monitoring the status of preterm infants in the Neonatal Intensive Care Unit (NICU) provides a unique and challenging environment for the design, function and use of sensor-based monitoring equipment. This article presents an overview of sensor-based instrumentation used in the NICU for physiological and chemical status monitoring, and discusses some of the key sensing principles currently in use. The clinical demand for reliable patient data at acceptable cost is driving the development of new types of monitoring technologies, in particular for continuous blood-chemistry analysis.