The London Centre for Nanotechnology is a multidisciplinary research centre in physical and biomedical nanotechnology in London, United Kingdom. It brings together three institutions that are world leaders in nanotechnology, University College London, Imperial College London and King's College London. It was conceived from the outset with a management structure allowing for a clear focus on exploitation and commercialisation. Although based at UCL's campus in Bloomsbury, the LCN includes research in departments of Imperial's South Kensington campus and in King's Strand campus.The LCN's work requires it to draw on the combined skills of multiple departments, including medicine, chemistry, physics, electrical and electronic engineering, biochemical engineering, materials and earth sciences, and two leading business centres. The LCN's stated vision is to become Europe's premier research centre in nanotechnology applied to health care, information technology and the environment.
Recently proposed metastability-induced quantum batteries have shown particular promise for coherent microwave generation. However, achieving high-power coherent microwave generation in quantum batteries remains fundamentally challenging due to quantum correlations, aging, and self-discharging processes. For the cavity-quantum-electrodynamics-based quantum batteries, a further trade-off arises between strong spin-photon coupling for energy storage and sufficient output coupling for power delivery. To overcome these constraints, we introduce dissipation engineering as a dynamic control strategy that temporally separates energy storage and release. By suppressing emission during charging and rapidly enhancing the output coupling during discharging, we realize nanosecond microwave bursts with watt-level peak power. By optimizing three dissipation schemes, we improve work extraction efficiency of the quantum battery by over 2 orders of magnitude and achieve high-power compression factors outperforming the state-of-the-art techniques, establishing dissipation engineering as a pathway toward room-temperature, high-power coherent microwave sources.
Electron paramagnetic resonance (EPR) spectroscopy is a widely used technique for the characterization of paramagnetic centers across a wide range of disciplines. Yet, the detection limits of conventional 3D microwave resonators hinder the application of EPR to nanoscale and magnetically dilute thin films relevant to quantum, catalytic and biological devices. Here we show that high temperature superconducting spiral microresonators fabricated from YBa2Cu3O7-x enable pulse EPR measurements on diverse thin films with a sensitivity improvement of two to three orders of magnitude over commercial resonators. Templated 50 nm films of copper phthalocyanine (CuPc) diluted in metal-free phthalocyanine (H2Pc) deposited onto the microresonator were detectable in echo-detected EPR field sweeps with the templating effect clearly visible from narrowing of the spectrum compared to powder samples. The number of Cu(II) spins present in a single thin film of CuPc on a microresonator with 400 μm diameter was ~1011, as determined by measurement of coherence memory times (Tm) and longitudinal (T1) spin relaxation times. The Carr-Purcell-Meiboom-Gill (CPMG) sequence was also employed, enabling improved SNR by averaging multiple echoes obtained from echo trains. To demonstrate biological application, Cu,Zn superoxide dismutase (SOD) was incorporated into trehalose films of ~3.7 μm average thickness, containing ~1012 Cu(II) centers. Hyperfine spectroscopy (ESEEM and HYSCORE) was successfully performed on the SOD films, producing spectra that match conventional measurements taken with ~104 times more enzyme. These results establish superconducting microresonators as a versatile high-sensitivity platform for pulse EPR of ultrathin and volume-limited films. The transformation of EPR from a ‘bulk’ to a ‘surface’ technique will facilitate the study of quantum materials, catalytic interfaces and bio-integrated devices.
Binary alloy phase diagrams at high pressure are essential for understanding solidification and chemical partitioning in both engineered materials and planetary interiors, yet their experimental determination becomes increasingly challenging under extreme conditions. We apply a fully ab initio approach [J. Chem. Phys. 162, 184502 (2025)], based on density-functional theory, to compute the dilute-limit phase diagram of the Al-Mg system from ambient conditions up to 150 GPa. As a first step, we calculate the melting curves of pure fcc Al and pure hcp/bcc Mg, including the hcp-bcc phase boundary and triple point of Mg, all of which agree closely with available experimental data. The binary phase diagram is then constructed at both compositional extremes. On the Al-rich side, Mg consistently favours the liquid throughout the entire pressure range, with this preference strengthening monotonically under compression. On the Mg-rich side, Al partitions preferentially into the liquid at ambient pressure but undergoes a complete reversal above 60 GPa, becoming solid-favouring as the Mg host transitions from hcp to bcc. This pressure-driven reversal inverts the topology of the Mg-rich coexistence field from a conventional downward-sloping to an upward-sloping phase boundary, and has direct implications for models of planetary differentiation and interior chemical stratification.
The scarcity of Ir presents a major challenge for scaling up its use as a water oxidation electrocatalyst in proton exchange membrane (PEM) water electrolysers. Developing conductive and stable supports is an effective way to reduce iridium loading while maintaining performance. However, the influence of support conductivity and stability on Ir-based catalytic activity remains poorly understood. The behaviour of the support is often obscured in conventional membrane electrode assembly (MEA) systems because IrOx itself is both highly conductive and exceptionally stable. To decouple support conductivity and passivation effects from the intrinsic conductivity of IrOx, we demonstrate a screening platform by studying a series of Ti-Nb alloy thin films produced by sputter deposition and investigate their performance as supports for IrOx water oxidation electrocatalysts. A range of electrochemical tests including accelerated stress tests (AST) were carried out on these samples, where characterisation techniques, including X-ray absorption spectroscopy (XAS), X-ray photoelectron spectroscopy (XPS) and high resolution transmission electron microscopy (HRTEM), demonstrated the in situ formation of passivation layers on these supports during water oxidation. Our results suggest that a similar to 10 nm oxide passivation layer forms on metallic Ti-based supports. On alloying Nb with Ti metal, a more insulating rutile TiO2 phase forms during water oxidation whereas an anatase TiO2, with higher conductivity, is observed on the pure Ti support. Consequently, although alloying Ti with Nb improves the bulk conductivity, the structure of the oxide passivation layer results in a drastic decrease of conductivity and water oxidation activity. Our results demonstrate the importance of the structure and composition of surface oxide phases formed during water oxidation in controlling the overall stability and conductivity of support materials.
Simultaneous control over the directionality and spin of light at the nanoscale is a central goal in nanophotonics with applications ranging from quantum information to advanced biosensing. We introduce the concept of the Circular Huygens Dipole and numerically demonstrate its realization in a single Si nanocuboid. We show that the polarization of an incident linear wave controls the interference between co-located circular electric and magnetic dipoles excited in phase quadrature. This enables deterministic switching of the forward-scattered radiation between purely right- and left-circularly polarized states. The system also functions as a directional spin-to-linear polarization converter. Our findings establish a robust, passive method for reconfigurable spin-directional control in a simple, monolithic silicon nanostructure, opening avenues for chip-scale spin-optics, chiral quantum interfaces, and novel sensing platforms.
