Quantimony

Owing to the development of novel device capabilities grounded on materials quantum properties, a technological revolution is expected to boost our life quality in the coming years. These fascinating advances are mostly based on the exploitation of nanotechnology, which involves not only a reduction of the device’s size, but also extraordinary properties triggered at the nanoscale. To produce these breakthroughs, several semiconductor materials are under exhaustive exploration. In particular, recent investigations have demonstrated the exceptional potential of Sb-based compounds to rational tailor unique optical and electrical mechanisms within nanodevices.

In terms of quantum technology, the need for faster computing performance by means of quantum operations reached a higher level with the discovery of Majorana zero modes in topological systems. Arrays of nanowire semiconductor-superconductors showed evidence of Majorana fermions for ultrafast logical operations. These observations were reported in InSb nanowire-based systems, which are able to provide fast qubit manipulation. As a result, InSb has been consolidated as one of the most promising candidates for the fabrication of quantum computing nanodevices.

However, several difficulties remain critical challenges. For example, the reduction of structural disorder is a fundamental issue to make the topological properties accessible. Accordingly, only a combination of analytical techniques with high sensitivity and nanoscale spatial resolution can give a comprehensive examination of the structural-transport relationships to overcome these obstacles. In this context, a multimodal hard X-ray nanoprobe from a fourth generation synchrotron source provides an ideal tool to address these fundamental questions in InSb nanowire research under operando conditions.

In general terms, a synchrotron facility is a large machine (up to four times the size of a football field) that accelerates electrons to almost the speed of light. As the electrons are deflected through magnetic fields they create extremely bright light. The light is channeled down beamlines to experimental workstations where it is exploited for research. Within the wavelength regime, the synchrotron beamlines can cover a multi-eV electromagnetic spectrum, ranging from the IR domain, moving upward through soft and hard X-rays up to even gamma rays, offering versatility and complementarity. Most of these beamlines host multiple techniques with temporal and spatial resolutions, relying on the richness of photon-matter interaction mechanisms. The large variety of X-ray absorption spectroscopic, scattering, imaging and diffraction methods provides crucial molecular- and atomic-scale information to unveil the secrets of matter. The great advantage of synchrotron light is its tremendously high brilliance, which is 10 trillion times brighter than hospital X-rays machines. In 2020, a dream come true with the launch of the first high-energy, fourth generation synchrotron at the European Synchrotron Radiation Facility (ESRF): The Extremely Brilliant Source (EBS). With X-ray beams 100 times brighter than its predecessor, the world’s brightest synchrotron light source opens a new era for science to understand the complexity of materials at unprecedent levels.

In parallel, several routes for X-ray nanofocusing have been developed in the last two decades based on highly sophisticated and reliable schemes to meet the important research challenges. Operando approaches (magnetic and electric fields), extreme thermodynamic conditions (T,P) and in-situ sample environments (e.g., gasses, humidity) at the nanometer length scales have been implemented to get direct and deeper insights into composition, structure as well as property-function interconnections in 2D and 3D. As a result, the X-ray nanoprobes currently present more integration of complementary methods for time- and space-resolved (4D) studies with static and dynamic multiscale approaches.

Therefore, hard X-ray nanoprobes are excellent instruments to obtain a full picture of the structural disorder in InSb nanowire-based systems. The resulting performance depends on small temporal and/or spatial variations in composition and atomic-scale structure extending in nanometer range. The use of advanced hard X-ray nanoprobes under real conditions constitute an efficient strategy to explain and anticipate the InSb related properties and functionalities at the atomic level, nondestructively with high sensitivity. Overall, the operando X-ray nanoanalysis can capture key operation mechanisms of nanodevices (charging, switching, recording, reading, writing, erasing), mitigation or failure processes under real working conditions, offering full potential from the interplay on property – function relationships through correlative and combinatorial examination performed simultaneously.

In summary, looking through this perspective, the use of synchrotron analytical techniques can be a key element for the development of new technologies and devices. That is the reason why, as part of Quantimony network, in operando synchrotron nanoprobe investigations are performed in different Sb-based devices, such as InSb nanonetworks for Majorana studies, to contribute to a solid knowledge and consolidation of Sb-based technologies.