Research Bits: July 5

UTe2 breakthrough for quantum computing

Scientists from the Macroscopic Quantum Matter Group laboratory at the University College Cork (UCC) in Ireland discovered a spatially modulating superconducting state in the superconductor uranium ditelluride (UTe2) that could be useful as in topological quantum computing. Using a powerful quantum microscope, the team found that the some of the electrons pairs created a new crystal structure in a background macroscopic quantum mechanical fluid. “These types of states were first discovered by our group in 2016 and are now called electron pair-density waves. These pair density waves are a new form of superconducting matter the properties of which we are still discovering,” said Joe Carroll, lead author and PhD researcher at UCC in a press release. Scientists have been interested in the strange properties of UTe2 since it was discovered in 2018.  “What our team found was that some of the electron pairs form a new crystal structure embedded in this background fluid. These types of states were first discovered by our group in 2016 and are now called electron pair-density waves. These pair density waves are a new form of superconducting matter the properties of which we are still discovering.”

Other universities that participated in the experiments were Clarendon Laboratory (University of Oxford, Oxford, UK); Department of Physics (Washington University in St. Louis, St. Louis, MO, USA); Maryland Quantum Materials Center (University of Maryland, College Park, MD, USA); NIST Center for Neutron Research (Gaithersburg, MD, USA); Canadian Institute for Advanced Research (Toronto, Ontario, Canada); Max Planck Institute for Chemical Physics of Solids (Dresden, Germany); Department of Physics and Astronomy (University of Notre Dame, Notre Dame, IN, USA); and Stavropoulos Center for Complex Quantum Matter (University of Notre Dame, Notre Dame, IN, USA).

Gu, Q., Carroll, J.P., Wang, S. et al. Detection of a pair density wave state in UTe2. Nature 618, 921–927 (2023). https://doi.org/10.1038/s41586-023-05919-7

Single-molecule electronic ‘switch’

Researchers from University of Illinois Urbana-Champaign and Texas A&M University have identified a new organic material that holds promise as a single-molecule switch, which could function like a transistor.  A ladder-type oligoaniline derivative forms a unique structure by locking into a linear molecular backbone that cannot be rotated. The ladder-type structure adds stability and prevents hydrolysis (chemical breakdown when exposed to water). The material is conductive, can be cycled on/off many times controlled using chemical or electrochemical stimuli, and has different molecular states.

“The molecular scale switch has been a very popular subject in studies of single molecule electronics,” said lead author and former graduate student Jialing (Caroline) Li in a press release. “But realizing a multi-state switch on a molecular scale is challenging because we require a material that is conductive and has several different molecular charge states, and we require the material to be very stable so it can be switched on and off for many cycles.” The ladder-type oligoaniline derivative is conductive and stable.

Jialing Li, Bo-Ji Peng, Shi Li, Daniel P. Tabor, Lei Fang, Charles M. Schroeder. Ladder-type conjugated molecules as robust multi-state single-molecule switches. Chem, 2023; DOI: 10.1016/j.chempr.2023.05.001

Microcapsule sensors from seaweed, graphene

Researchers from Queen Mary University and University of Sussex in the U.K. have created nanocomposite microcapsules from graphene gel mixed with seaweed that can be networked to create sensing devices worn on the skin for taking accurate real-time biological measurements. The electrical property of the capsules changes when pressure is applied, and the capsules are very sensitive to pressure. The capsules are biodegradable and reduce plastic waste.

“We harnessed the extraordinary properties of newly-created seaweed-graphene microcapsules that redefine the possibilities of wearable electronics,” said Dimitrios Papageorgiou, lecturer in materials science at Queen Mary University of London. “Our discoveries offer a powerful framework for scientists to reinvent nanocomposite wearable technologies for high precision health diagnostics, while our commitment to recyclable and biodegradable materials is fully aligned with environmentally conscious innovation.”

Adel K. A. Aljarid, Ming Dong, Yi Hu, Cencen Wei, Jonathan P. Salvage, Dimitrios G. Papageorgiou, Conor S. Boland. Smart Skins Based on Assembled Piezoresistive Networks of Sustainable Graphene Microcapsules for High Precision Health Diagnostics. Advanced Functional Materials, 2023; DOI: 10.1002/adfm.202303837