Tue 11 Feb 14:00: Symmetric Quantum Computation
A central challenge in quantum computing is to discern which types of problems allow for quantum algorithms that substantially outperform classical ones. Underlying this challenge is an even more fundamental question: what general characteristics of computational problems make them more (or less) amenable to quantum methods? In this talk I will present my personal attempts to make progress on this fundamental question.
I will introduce a new framework of quantum computation where the symmetries of the problem in consideration play a key role. This framework was developed with the view to elucidate the role of symmetries on quantum speedups, and forms a natural quantum extension of symmetric threshold circuits—a common core where multiple notions of symmetry in classical computation converge. I aim to motivate our computational model and show how it can go beyond the capabilities of its classical counterpart. Several open problems will be presented, which I hope can pave the way for future progress on my earlier question.
This talk is based on joint work with Tom Gur and Sergii Strelchuk.
- Speaker: Davi Castro-Silva (Cambridge)
- Tuesday 11 February 2025, 14:00-15:00
- Venue: Computer Laboratory, William Gates Building, Room SS03.
- Series: Quantum Computing Seminar; organiser: Tom Gur.
Tue 25 Feb 14:00: Title to be confirmed
Abstract not available
- Speaker: Kyle Beadle, UCL
- Tuesday 25 February 2025, 14:00-15:00
- Venue: Webinar & FW11, Computer Laboratory, William Gates Building..
- Series: Computer Laboratory Security Seminar; organiser: Tina Marjanov.
Wed 19 Mar 14:15: The Schubert variety of a hyperplane arrangement
I’ll tell you about some of my favorite algebraic varieties, which are beautiful in their own right, and also have some dramatic applications to algebraic combinatorics. These include the top-heavy conjecture (one of the results for which June Huh was awarded the Fields Medal), as well as non-negativity of Kazhdan—Lusztig polynomials of matroids.
- Speaker: Nicholas Proudfoot, University of Oregon
- Wednesday 19 March 2025, 14:15-15:15
- Venue: CMS MR13.
- Series: Algebraic Geometry Seminar; organiser: Dhruv Ranganathan.
Thu 03 Apr 16:00: 2024 Novo Nordisk Prize Lectures
Shankar and David will deliver the 2024 Novo Nordisk Lectures. Shankar’s will talk on Decoding DNA and David the applications of physical sciences to biomedicine, next generation DNA sequencing and beyond. This will be followed by a drinks reception hosted by the Novo Nordisk foundation.
- Speaker: Professors Sir Shankar Balasubramanian and Sir David Klenerman
- Thursday 03 April 2025, 16:00-17:30
- Venue: Dept of Chemistry, (BMS) Bristol Myers Squibb Lecture Theatre.
- Series: Chemistry Departmental-wide lectures; organiser: Balasubramanian-Admin.
Fri 04 Apr 10:30: Frontiers in Biophysics and Chemical Biology symposium
Funded by the Novo Nordisk Foundation and chaired by the 2024 Novo Nordisk Prize winners, Professors Sir Shankar Balasubramanian and Sir David Klenerman, this one day symposium brings together world leading scientists in the field of biophysics and chemical biology at the Yusuf Hamied Department of Chemistry.
The speakers are Professor Ed Boyden, MIT ; Professor Jason Chin, University of Cambridge; Professor Thomas Carrell from LMU , Munich; Professor Chuan He, University of Chicago; and Professor Xiaowei Zhang, Harvard University.
To register: https://www.eventbrite.co.uk/e/frontiers-in-biophysics-and-chemical-biology-tickets-1224872329109?aff=oddtdtcreator
- Speaker: Professor Ed Boyden, MIT; Professor Jason Chin, University of Cambridge; Professor Thomas Carrell from LMU, Munich; Professor Chuan He, University of Chicago; and Professor Xiaowei Zhang, Harvard University.
- Friday 04 April 2025, 10:30-17:00
- Venue: Dept of Chemistry, (BMS) Bristol Myers Squibb Lecture Theatre.
- Series: Chemistry Departmental-wide lectures; organiser: Balasubramanian-Admin.
Wed 12 Feb 14:00: Short-term, high-resolution sea ice forecasting with diffusion model ensembles
Sea ice plays a key role in Earth’s climate system and exhibits significant seasonal variability as it advances and retreats across the Arctic and Antarctic every year. The production of sea ice forecasts provides great scientific and practical value to stakeholders across the polar regions, informing shipping, conservation, logistics, and the daily lives of inhabitants of local communities. Machine learning offers a promising means by which to develop such forecasts, capturing the nonlinear dynamics and subtle spatiotemporal patterns at play as effectively—if not more effectively—than conventional physics-based models. In particular, the ability of deep generative models to produce probabilistic forecasts which acknowledge the inherent stochasticity of sea ice processes and represent uncertainty by design make them a sensible choice for the task of sea ice forecasting. Diffusion models, a class of deep generative models, present a strong option given their state-of-the-art performance on computer vision tasks and their strong track record when adapted to spatiotemporal modelling tasks in weather and climate domains. In this talk, I will present preliminary results from a IceNet-like [1] diffusion model trained to autoregressively forecast daily, 6.25 km resolution sea ice concentration in the Bellingshausen Sea along the Antarctic Peninsula. I will also touch on the downstream applications for these forecasts, from conservation to marine route planning, which are under development at the British Antarctic Survey (BAS). I welcome ideas and suggestions for improvement and look forward to discussing opportunities for collaboration within and beyond BAS .
[1] Andersson, Tom R., et al. “Seasonal Arctic sea ice forecasting with probabilistic deep learning.” Nature communications 12.1 (2021): 5124. https://www.nature.com/articles/s41467-021-25257-4
- Speaker: Andrew McDonald, University of Cambridge and British Antarctic Survey
- Wednesday 12 February 2025, 14:00-15:00
- Venue: BAS Seminar Room 2; https://ukri.zoom.us/j/96472472041.
- Series: British Antarctic Survey - Polar Oceans seminar series; organiser: Dr Birgit Rogalla.
Lithium-selective “OR-gate” enables fast-kinetics and ultra-stable Li-rich cathodes for polymer-based solid-state batteries
DOI: 10.1039/D4EE05264A, PaperQin Wang, Yiming Zhang, Meng Yao, Kang Li, Lv Xu, Haitao Zhang, Xiaopeng Wang, Yun Zhang
The utilization of high-capacity lithium-rich layered oxide (LRLO) in lithium-ion batteries is hampered by its severe interface reactions and poor interface dynamics. Herein, an OG gate (OG) is constructed on...
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Soft‐Actuated Cuff Electrodes with Minimal Contact for Bidirectional Peripheral Interfaces
Soft-actuated cuff electrodes (SACE) for bidirectional peripheral interfaces enable minimal and secure contact to the nerve through fluid injection-based soft actuation. A 3D bent structure can grasp and securely contact the nerves with only a little pressure (<1.21 gram-force). The SACE can achieve negligible damage to the nerve during recording of sensory and motor feedback signals with superior SNR and neuromodulation for long-term studies.
Abstract
Neural interfaces with embedded electrical functions, such as cuff electrodes, are essential for monitoring and stimulating peripheral nerves. Still, several challenges remain with cuff electrodes because sutured devices can damage the nerve by high pressure and the secured contact of electrodes with the nerve is hard to accomplish, which however is essential in maintaining electrical performance. Here, a sutureless soft-actuated cuff electrodes (SACE) that can envelop the nerve conveniently by creating a bent shape controlled upon fluid injection, is introduced. Moreover, fluid injection protrudes part of the device where electrodes are formed, thereby achieving minimized, soft but secure contact between the electrodes and the nerve. In vivo results demonstrate the successful recording and stimulation of peripheral nerves over time up to 6 weeks. While securing contact with the nerve, the implanted electrodes can preserve the nerve intact with no reduction in blood flow, thereby indicating only minimal compressive force applied to the nerve. The SACE is expected to be a promising tool for recording and stimulation of peripheral nerves toward bidirectional neuroprostheses.
Tailorable Fluorescent Perovskite Quantum Dots for Multiform Manufacturing via Two‐Step Thiol‐Ene Click Chemistry
A novel UV-induced two-step thiol-ene “click chemistry” is introduced for the tailorable fluorescent perovskite quantum dots (T-PQDs). A protective shell is formed around the PQDs in the first step, while chemical cross-linking between PQD and thiol-ene polymer occurs in the second step. The T-PQDs offer high efficiency, stability, and processability, facilitating their multiform manufacturing for a wide range of applications.
Abstract
In practical applications, fluorescent perovskite quantum dots (PQDs) must exhibit high efficiency, stability, and processibility. So far, it remains a challenge to synthesize PQDs with stable dispersibility in tailorable monomers both before and after photocuring. In this work, a novel strategy of UV-induced two-step thiol-ene “click chemistry” is proposed to prepare PQDs with these attributes. The first step aims to epitaxially grow a shell around the PQD core to ensure stable dispersibility in a thiol-ene monomer solution. The second step is to achieve stable dispersibility in the photocured thiol-ene matrixes for multiform manufacturing processes. The tailorable PQDs (T-PQDs) not only have the highest photoluminescence quantum yield (PLQY) to ≈100% for green emission and over 96% for red emission, but also exhibit remarkable stability under severe conditions, including “double 85” aging, water exposure, and mechanical stress. Moreover, their exceptional processability allows for various processing techniques, including slot-die coating, inkjet printing, direct-laser writing, UV-light 3D printing, nanoimprinting, and spin coating. The high efficiency and stability of T-PQDs facilitate their multiform manufacturing for a wide range of applications.
High‐Temperature Resistance Photoluminescence Carbonized Polymer Dots Through Equilibrium Bi‐Confinement Effects
In this study, bi-confinement effects arising from a highly cross-linked polymer network and rigid Al₂O₃ matrix are exploited to achieve ultra-stable carbonized polymer dots (CPDs). The obtained CPDs@Al2O3 composite demonstrates exceptional long-term stability in various solvents and high photoluminescence emission thermotolerance up to 500 K for 150 h, representing the best performance of carbon dots under harsh conditions reported to date.
Abstract
Carbon dots are emerging luminescent nanomaterials that have drawn considerable attention due to their abundance, environmental friendliness, and customizable optical properties. However, their susceptibility to temperature-induced vibrational exciton changes and the tendency to thermal quenching of emission have hindered their practical applications. Here, a method is reported for achieving high-temperature photoluminescence carbonized polymer dots (CPDs) through a bi-confinement approach that involves a highly cross-linked polymer network and a rigid Al2O3 matrix. As the temperature increased from 303 to 500 K, the fluorescence and phosphorescence emission intensities of CPDs@Al2O3 remained virtually unchanged, with the emission duration exceeding 150 h at 500 K. Additionally, CPDs@Al2O3 composites with different degrees of carbonization exhibit dynamic excitation-dependent photoluminescence properties, which can be patterned for multiple information encryption application. This work provides a concept for designing stable and luminous CPDs under harsh conditions, thus expanding their potential application range.
Stretchable Multimodal Photonic Sensor for Wearable Multiparameter Health Monitoring
A stretchable multimodal photonic sensor capable of simultaneously detecting and discriminating strain deformations, temperature, and sweat pH is developed for on-skin health monitoring. By integrating multiple sensing mechanisms in a single hydrogel-coated PDMS optical fiber (HPOF) at distinct wavelengths, the device achieves simultaneous monitoring of heartbeat, respiration, body temperature, and sweat pH of a person in real-time with negligible crosstalk.
Abstract
Stretchable sensors that can conformally interface with the skins for wearable and real-time monitoring of skin deformations, temperature, and sweat biomarkers offer critical insights for early disease prediction and diagnosis. Integration of multiple modalities in a single stretchable sensor to simultaneously detect these stimuli would provide a more comprehensive understanding of human physiology, which, however, has yet to be achieved. Here, this work reports, for the first time, a stretchable multimodal photonic sensor capable of simultaneously detecting and discriminating strain deformations, temperature, and sweat pH. The multimodal sensing abilities are enabled by realization of multiple sensing mechanisms in a hydrogel-coated polydimethylsiloxane (PDMS) optical fiber (HPOF), featured with high flexibility, stretchability, and biocompatibility. The integrated mechanisms are designed to operate at distinct wavelengths to facilitate stimuli decoupling and employ a ratiometric detection strategy for improved robustness and accuracy. To simplify sensor interrogation, spectrally-resolved multiband emissions are generated upon the excitation of a single-wavelength laser, utilizing upconversion luminescence (UCL) and radiative energy transfer (RET) processes. As proof of concept, this work demonstrates the feasibility of simultaneous monitoring of the heartbeat, respiration, body temperature, and sweat pH of a person in real-time, with only a single sensor.
Issue Information
Scalable Multistep Roll‐to‐Roll Printing of Multifunctional and Robust Reentrant Microcavity Surfaces via a Wetting‐Induced Process (Adv. Mater. 5/2025)
Wetting-Induced Process
The wetting-induced interconnected reentrant geometry (WING) process enables the large-scale fabrication of multifunctional re-entrant microcavity surfaces, representing a significant technological advancement. Utilizing capillary action in a scalable roll-to-roll printing technique, it produces surfaces with exceptional liquid repellency while maintaining microstructures under external forces. This process offers a cost-effective and high throughput solution for various applications, such as anti-icing, anti-fouling, and particle capture. More details can be found in article number 2411064 by Seok Kim, Young Tae Cho, and co-workers.
Multiscale Manufacturing of Recyclable Polyimide Composite Aerogels (Adv. Mater. 5/2025)
Recyclable Polyimide Composite Aerogels
In article number 2411599 by Wim J. Malfait, Qinghua Zhang, Shanyu Zhao, and co-workers, a molecular design strategy was employed to facilitate the formation and controlled disassembly of high-performance, recyclable polyimide composite aerogels. The innovative “aerogel-in”aerogel" structure exhibits a highly porous, interpenetrating architecture with complete disaggregation capabilities. This composite showcases exceptional resistance to extreme conditions, spanning from ultra-low temperatures of −196 °C to ultra-high environments of 800 °C, providing a groundbreaking and sustainable solution for next-generation thermal protection materials.
Single‐Cell Isolation Chip Integrated with Multicolor Barcode Array for High‐Throughput Single‐Cell Exosome Profiling in Tissue Samples (Adv. Mater. 5/2025)
Single-Cell Exosome
The background shows a microwell array chip with a light beam symbolizing photothermal technology for single-cell isolation. A magnified view highlights exosome secretion by a purple cell. Multicolored markers identify different exosomes. More details can be found in article number 2411259 by Lin Han and co-workers.
Polymorphing Hydrogels Regulated by Photo‐reactive DNA Cross‐links (Adv. Mater. 5/2025)
Polymorphing Hydrogels – Sculpting with Light
Polymorphing hydrogels can be reshaped on demand by shining light on specific areas. These hydrogels incorporate photo-reactive DNA cross-links, whose lengths are reversibly controlled by UV or visible light. Under UV illumination, the cross-links shorten, causing the hydrogel to contract, while exposure to visible light restores their original length. The image symbolizes this process by depicting a “VIS”ible man and “UV”men working together to sculpt the material. More details can be found in article number 2414648 by Eunjin Choi, Yeongjae Choi, and co-workers.
Tailorable Fluorescent Perovskite Quantum Dots for Multiform Manufacturing via Two‐Step Thiol‐Ene Click Chemistry (Adv. Mater. 5/2025)
Perovskite Quantum Dots
Inspired by the hedgehog, the fluorescent perovskite quantum dots (PQDs) with a defending layer are designed via using thiol-ene “click chemistry”. Benefiting from the high colloidal dispersion of PQDs in the photo-curable matrixes, the PQDs offer high efficiency, stability, and processability, facilitating their multiform manufacturing for a wide range of applications, even for underwater displays. More details can be found in article number 2411453 by Zuliang Du and co-workers.
Local Chemical Enhancement and Gating of Organic Coordinated Ionic‐Electronic Transport (Adv. Mater. 5/2025)
Organic Electronics
Record ion mobility and conductivities are revealed within a nanoscopic interfacial superhighway of an organic mixed ionic-electronic conductor. Fast ion transport can be controlled by hydrophobicity of molecules local to this channel, effectively gating ion access to the superhighway. This mechanism is used in a novel chemical sensing device which detects the dynamics of a local, buried chemical reaction. More details can be found in article number 2406281 by Tamanna Khan, Terry McAfee, Thomas J. Ferron, Awwad Alotaibi, and Brian A. Collins.
Soft‐Actuated Cuff Electrodes with Minimal Contact for Bidirectional Peripheral Interfaces (Adv. Mater. 5/2025)
Soft-Actuated Cuff Electrodes
A sutureless, soft-actuated cuff electrodes (SACE) device envelops a nerve by itself upon fluid injection into part of the device made of soft and expandable polymeric structures. Three-dimensionally protruded part of the device ensures soft, minimal but secure contact between electrodes and nerve, resulting in superior performance in signal recording. More details can be found in article number 2409942 by Sohee Kim and co-workers.
Hierarchically Promoted Light Harvesting and Management in Photothermal Solar Steam Generation
This review examines the critical role of multi-scale hierarchical structures, from molecular to macro levels, in optimizing light harvesting and photothermal efficiency in solar steam generation (SSG) systems. By tailoring materials and structures to enhance light absorption, manage thermal properties, and support effective water transport, these integrated designs advance solar-thermal desalination as a sustainable solution to water scarcity.
Abstract
Solar steam generation (SSG) presents a promising approach to addressing the global water crisis. Central to SSG is solar photothermal conversion that requires efficient light harvesting and management. Hierarchical structures with multi-scale light management are therefore crucial for SSG. At the molecular and sub-nanoscale levels, materials are fine-tuned for broadband light absorption. Advancing to the nano- and microscale, structures are tailored to enhance light harvesting through internal reflections, scattering, and diverse confinement effects. At the macroscopic level, light capture is optimized through rationally designed device geometries, configurations, and arrangements of solar absorber materials. While the performance of SSG relies on various factors including heat transport, physicochemical interactions at the water/air and material/water interfaces, salt dynamics, etc., efficient light capture and utilization holds a predominant role because sunlight is the sole energy source. This review focuses on the critical, yet often underestimated, role of hierarchical light harvesting/management at different dimensional scales in SSG. By correlating light management with the structure-property relationships, the recent advances in SSG are discussed, shedding light on the current challenges and possible future trends and opportunities in this domain.