̽��ֱ�� of Cambridge - photonics

Cambridge to trial cutting-edge semiconductor technologies for wider use in major European project

sc604 — Tue, 10 Dec 2024 10:34:10 +0000

Photonic chips transmit and manipulate light instead of electricity, and offer significantly faster performance with lower power consumption than traditional electronic chips. 

̽��ֱ��Cambridge Graphene Centre and Cornerstone Photonics Innovation Centre at the ̽��ֱ�� of Southampton will partner with members from across Europe to host a pilot line, coordinated by the Institute of Photonic Sciences in Spain, combining state-of-the-art equipment and expertise from 20 research organisations.

̽��ֱ��PIXEurope consortium has been selected by the European Commission and Chips Joint Undertaking, a European initiative aiming to bolster the semiconductor industry by fostering collaboration between member states and the private sector. ̽��ֱ��consortium is supported by €380m in total funding.

̽��ֱ��UK participants will be backed by up to £4.2 million in funding from the Department of Science, Innovation and Technology (DSIT), match-funded by Horizon Europe. ̽��ֱ��UK joined the EU’s Chips Joint Undertaking in March 2024, allowing the country to collaborate more closely with European partners on semiconductor innovation.

̽��ֱ��new pilot line will combine state-of-the-art equipment and expertise from research organisations across 11 countries. It aims to encourage the adoption of cutting-edge photonic technologies across more industries to boost their efficiency.

Photonic chips are already essential across a wide range of applications, from tackling the unprecedented energy demands of datacentres, to enabling high-speed data transmission for mobile and satellite communications. In the future, these chips will become ever more important, unlocking new applications in healthcare, AI and quantum computing. 

Researchers at the Cambridge Graphene Centre will be responsible for the integration of graphene and related materials into photonic circuits for energy efficient, high-speed communications and quantum devices. “This may lead to life-changing products and services, with huge economic benefit for the UK and the world,” said Professor Andrea C. Ferrari, Director of the Cambridge Graphene Centre.

̽��ֱ��global market for photonic integrated circuits (PICs) production is expected to grow by more than 400% in the next 10 years. By the end of the decade, the global photonics market is expected to exceed €1,500bn, a figure comparable to the entire annual gross domestic product of Spain.

This growth is due to the demand from areas such as telecommunications, artificial intelligence, image sensing, automotive and mobility, medicine and healthcare, environmental care, renewable energy, defense and security, and a wide range of consumer applications.

̽��ֱ��combination of microelectronic chips and photonic chips provides the necessary features and specifications for these applications. ̽��ֱ��former are responsible for information processing by manipulating electrons within circuits based on silicon and its variants, while the latter uses photons in the visible and infrared spectrum ranges in various materials.

̽��ֱ��new pilot line aims to offer cutting-edge technological platforms, transforming and transferring innovative and disruptive integrated photonics processes and technologies to accelerate their industrial adoption. ̽��ֱ��objective is the creation of European-owned/made technology in a sector of capital importance for technological sovereignty, and the creation and maintenance of corresponding jobs in the UK and across Europe.

“My congratulations to Cornerstone and the Cambridge Graphene Centre on being selected to pioneer the new pilot line – taking a central role in driving semiconductor innovation to the next level, encouraging adoption of new technologies,” said Science Minister Lord Vallance. “ ̽��ֱ��UK laid the foundations of silicon photonics in the 1990s, and by pooling our expertise with partners across Europe we can address urgent global challenges including energy consumption and efficiency.”

“ ̽��ֱ��UK’s participation in the first Europe-wide photonics pilot line marks the start of the world’s first open access photonics integrated circuits ecosystem, stimulating new technology development with industry and catalyse disruptive innovation across the UK, while strengthening UK collaboration with top European institutions working in the field,” said Ferrari.

“PIXEurope is the first photonics pilot line that unifies the whole supply chain from design and fabrication, to testing and packaging, with technology platforms that will support a broad spectrum of applications,” said CORNERSTONE Coordinator Professor Calum Littlejohns. “I am delighted that CORNERSTONE will form a crucial part of this programme.”

̽��ֱ��Chips JU will also launch new collaborative R&D calls on a range of topics in early 2025. UK companies and researchers are eligible to participate.

̽��ֱ�� ̽��ֱ�� of Cambridge is one of two UK participants named as part of the PIXEurope consortium, a collaboration between research organisations from across Europe which will develop and manufacture prototypes of their products based on photonic chips.

̽��ֱ��text in this work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License. Images, including our videos, are Copyright © ̽��ֱ�� of Cambridge and licensors/contributors as identified. All rights reserved. We make our image and video content available in a number of ways – on our main website under its Terms and conditions, and on a range of channels including social media that permit your use and sharing of our content under their respective Terms.

Yes

Stackable ‘holobricks’ can make giant 3D images

sc604 — Wed, 16 Mar 2022 00:53:32 +0000

̽��ֱ��researchers, from the ̽��ֱ�� of Cambridge and Disney Research, developed a holobrick proof-of-concept, which can tile holograms together to form a large seamless 3D image. This is the first time this technology has been demonstrated and opens the door for scalable holographic 3D displays. ̽��ֱ��results are reported in the journal Light: Science & Applications.

As technology develops, people want high-quality visual experiences, from 2D high-resolution TV to 3D holographic augmented or virtual reality, and large true 3D displays. These displays need to support a significant amount of data flow: for a 2D full HD display, the information data rate is about three gigabits per second (Gb/s), but a 3D display of the same resolution would require a rate of three terabits per second, which is not yet available.

Holographic displays can reconstruct high-quality images for a real 3D visual perception. They are considered the ultimate display technology to connect the real and virtual worlds for immersive experiences.

“Delivering an adequate 3D experience using the current technology is a huge challenge,” said Professor Daping Chu from Cambridge’s Department of Engineering, who led the research. “Over the past ten years, we’ve been working with our industrial partners to develop holographic displays which allow the simultaneous realisation of large size and large field-of-view, which needs to be matched with a hologram with a large optical information content.”

However, the information content of current holograms information is much greater than the display capabilities of current light engines, known as spatial light modulators, due to their limited space bandwidth product.

For 2D displays, it’s standard practice to tile small size displays together to form one large display. ̽��ֱ��approach being explored here is similar, but for 3D displays, which has not been done before. “Joining pieces of 3D images together is not trivial, because the final image must be seen as seamless from all angles and all depths,” said Chu, who is also Director of the Centre for Advanced Photonics and Electronics (CAPE). “Directly tiling 3D images in real space is just not possible.”

To address this challenge, the researchers developed the holobrick unit, based on coarse integrated holographic displays for angularly tiled 3D images, a concept developed at CAPE with Disney Research about seven years ago.

Each of the holobricks uses a high-information bandwidth spatial light modulator for information delivery in conjunction with coarse integrated optics, to form the angularly tiled 3D holograms with large viewing areas and fields of view.

Careful optical design makes sure the holographic fringe pattern fills the entire face of the holobrick, so that multiple holobricks can be seamlessly stacked to form a scalable spatially tiled holographic image 3D display, capable of both wide field-of-view angle and large size.

̽��ֱ��proof-of-concept developed by the researchers is made of two seamlessly tiled holobricks. Each full-colour brick is 1024×768 pixels, with a 40° field of view and 24 frames per second, to display tiled holograms for full 3D images.

“There are still many challenges ahead to make ultra-large 3D displays with wide viewing angles, such as a holographic 3D wall,” said Chu. “We hope that this work can provide a promising way to tackle this issue based on the currently limited display capability of spatial light modulators.”

Reference:
Jin Li; Quinn Smithwick; Daping Chu. ‘Holobricks: Modular Coarse Integral Holographic Displays.’ Light: Science & Applications (2022). DOI: 10.1038/s41377-022-00752-7

Researchers have developed a new method to display highly realistic holographic images using ‘holobricks’ that can be stacked together to generate large-scale holograms.

CAPE

Reconstructed holographic images of a toy train (top) with holobricks and original image captured by a camera (bottom)

̽��ֱ��text in this work is licensed under a Creative Commons Attribution 4.0 International License. Images, including our videos, are Copyright © ̽��ֱ�� of Cambridge and licensors/contributors as identified. All rights reserved. We make our image and video content available in a number of ways – as here, on our main website under its Terms and conditions, and on a range of channels including social media that permit your use and sharing of our content under their respective Terms.

Yes

Colour-changing magnifying glass gives clear view of infrared light

sc604 — Thu, 02 Dec 2021 19:00:00 +0000

Detecting light beyond the visible red range of our eyes is hard to do, because infrared light carries so little energy compared to ambient heat at room temperature. This obscures infrared light unless specialised detectors are chilled to very low temperatures, which is both expensive and energy-intensive.

Now researchers led by the ̽��ֱ�� of Cambridge have demonstrated a new concept in detecting infrared light, showing how to convert it into visible light, which is easily detected.

In collaboration with colleagues from the UK, Spain and Belgium, the team used a single layer of molecules to absorb the mid-infrared light inside their vibrating chemical bonds. These shaking molecules can donate their energy to visible light that they encounter, ‘upconverting’ it to emissions closer to the blue end of the spectrum, which can then be detected by modern visible-light cameras.

̽��ֱ��results, reported in the journal Science, open up new low-cost ways to sense contaminants, track cancers, check gas mixtures, and remotely sense the outer universe.

̽��ֱ��challenge faced by the researchers was to make sure the quaking molecules met the visible light quickly enough. “This meant we had to trap light really tightly around the molecules, by squeezing it into crevices surrounded by gold,” said first author Angelos Xomalis from Cambridge’s Cavendish Laboratory.

̽��ֱ��researchers devised a way to sandwich single molecular layers between a mirror and tiny chunks of gold, only possible with ‘meta-materials’ that can twist and squeeze light into volumes a billion times smaller than a human hair.

“Trapping these different colours of light at the same time was hard, but we wanted to find a way that wouldn’t be expensive and could easily produce practical devices,” said co-author Dr Rohit Chikkaraddy from the Cavendish Laboratory, who devised the experiments based on his simulations of light in these building blocks.

“It’s like listening to slow-rippling earthquake waves by colliding them with a violin string to get a high whistle that’s easy to hear, and without breaking the violin,” said Professor Jeremy Baumberg of the NanoPhotonics Centre at Cambridge’s Cavendish Laboratory, who led the research.

̽��ֱ��researchers emphasise that while it is early days, there are many ways to optimise the performance of these inexpensive molecular detectors, which then can access rich information in this window of the spectrum.

From astronomical observations of galactic structures to sensing human hormones or early signs of invasive cancers, many technologies can benefit from this new detector advance.

̽��ֱ��research was conducted by a team from the ̽��ֱ�� of Cambridge, KU Leuven, ̽��ֱ�� College London (UCL), the Faraday Institution, and Universitat Politècnica de València.

̽��ֱ��research is funded as part of a UK Engineering and Physical Sciences Research Council (EPSRC) investment in the Cambridge NanoPhotonics Centre, as well as the European Research Council (ERC), Trinity College Cambridge and KU Leuven.

Jeremy Baumberg is a Fellow of Jesus College, Cambridge.

Reference:
Angelos Xomalis et al. ‘Detecting mid-infrared light by molecular frequency upconversion with dual-wavelength hybrid nanoantennas’, Science (2021). DOI: 10.1126/science.abk2593

By trapping light into tiny crevices of gold, researchers have coaxed molecules to convert invisible infrared into visible light, creating new low-cost detectors for sensing.

It’s like listening to slow-rippling earthquake waves by colliding them with a violin string to get a high whistle that’s easy to hear, and without breaking the violin

Jeremy Baumberg

NanoPhotonics Cambridge /Ermanno Miele, Jeremy Baumberg

Nano-antennas convert invisible infrared into visible light

Yes

Giant 'quantum twisters' may form in liquid light

sc604 — Fri, 05 Mar 2021 16:55:21 +0000

Anyone who has drained a bathtub or stirred cream into coffee has seen a vortex, a ubiquitous formation that appears when fluid circulates. But unlike water, fluids governed by the strange rules of quantum mechanics have a special restriction: as was first predicted in 1945 by future Nobel winner Lars Onsager, a vortex in a quantum fluid can only twist by whole-number units.

These rotating structures are predicted to be widely useful for studying everything from quantum systems to black holes. But while the smallest possible quantum vortex, with a single unit of rotation, has been seen in many systems, larger vortices are not stable. While scientists have attempted to force larger vortices to hold themselves together, the results have been mixed: when the vortices have been formed, the severity of the methods used have generally destroyed their usefulness.

Now, Samuel Alperin and Professor Natalia Berloff from the ̽��ֱ�� of Cambridge have discovered a theoretical mechanism through which giant quantum vortices are not only stable but form by themselves in otherwise near-uniform fluids. ̽��ֱ��findings, published in the journal Optica, could pave the way for experiments that might provide insight into the nature of rotating black holes that have similarities with giant quantum vortices.

To do this, the researchers used a quantum hybrid of light and matter, called a polariton. These particles are formed by shining laser light onto specially layered materials. “When the light gets trapped in the layers, the light and the matter become inseparable, and it becomes more practical to look at the resulting substance as something that is distinct from either light or matter, while inheriting properties of both,” said Alperin, a PhD student at Cambridge’s Department of Applied Mathematics and Theoretical Physics.

One of the most significant properties of polaritons comes from the simple fact that light can’t be trapped forever. A fluid of polaritons, which requires a high density of the exotic particles, is constantly expelling light, and needs to be fed with fresh light from the laser to survive. “ ̽��ֱ��result,” said Alperin, “is a fluid which is never allowed to settle, and which doesn’t need to obey what are usually basic restrictions in physics, like the conservation of energy. Here the energy can change as a part of the dynamics of the fluid.”

It was exactly these constant flows of liquid light that the researchers exploited to allow the elusive giant vortex to form. Instead of shining the laser on the polariton fluid itself, the new proposal has the light shaped like a ring, causing a constant inward flow similarly to how water flows to a bathtub drain. According to the theory, this flow is enough to concentrate any rotation into a single giant vortex.

“That the giant vortex really can exist under conditions that are amenable to their study and technical use was quite surprising,” Alperin said, “but really it just goes to show how utterly distinct the hydrodynamics of polaritons are from more well-studied quantum fluids. It’s exciting territory.”

̽��ֱ��researchers say that they are just at the beginning of their work on giant quantum vortices. They were able to simulate the collision of several quantum vortices as they dance around each other with ever increasing speed until they collide to form a single giant vortex analogous to the collision of black holes. They also explained the instabilities that limit the maximum vortex size while exploring intricate physics of the vortex behaviour.

“These structures have some interesting acoustic properties: they have acoustic resonances that depend on their rotation, so they sort of sing information about themselves,” said Alperin. “Mathematically, it’s quite analogous to the way that rotating black holes radiate information about their own properties.”

̽��ֱ��researchers hope that the similarity could lead to new insights into the theory of quantum fluid dynamics, but they also say that polaritons might be a useful tool to study the behaviour of black holes.

Professor Berloff is jointly affiliated with Cambridge and the Skolkovo Institute of Science and Technology in Russia.

Reference:
Samuel N. Alperin and Natalia G. Berloff. ‘Multiply charged vortex states of polariton condensates.’ Optica (2021). DOI: 10.1364/OPTICA.418377

New mechanism found for generating giant vortices in quantum fluids of light.

Stable giant quantum vortices

Yes

‘Multiplying’ light could be key to ultra-powerful optical computers

sc604 — Mon, 08 Feb 2021 10:26:02 +0000

An important class of challenging computational problems, with applications in graph theory, neural networks, artificial intelligence and error-correcting codes can be solved by multiplying light signals, according to researchers from the ̽��ֱ�� of Cambridge and Skolkovo Institute of Science and Technology in Russia.

In a paper published in the journal Physical Review Letters, they propose a new type of computation that could revolutionise analogue computing by dramatically reducing the number of light signals needed while simplifying the search for the best mathematical solutions, allowing for ultra-fast optical computers.

Optical or photonic computing uses photons produced by lasers or diodes for computation, as opposed to classical computers which use electrons. Since photons are essentially without mass and can travel faster than electrons, an optical computer would be superfast, energy-efficient and able to process information simultaneously through multiple temporal or spatial optical channels.

̽��ֱ��computing element in an optical computer – an alternative to the ones and zeroes of a digital computer – is represented by the continuous phase of the light signal, and the computation is normally achieved by adding two light waves coming from two different sources and then projecting the result onto ‘0’ or ‘1’ states.

However, real life presents highly nonlinear problems, where multiple unknowns simultaneously change the values of other unknowns while interacting multiplicatively. In this case, the traditional approach to optical computing that combines light waves in a linear manner fails.

Now, Professor Natalia Berloff from Cambridge’s Department of Applied Mathematics and Theoretical Physics and PhD student Nikita Stroev from Skolkovo Institute of Science and Technology have found that optical systems can combine light by multiplying the wave functions describing the light waves instead of adding them and may represent a different type of connections between the light waves.

They illustrated this phenomenon with quasi-particles called polaritons – which are half-light and half-matter – while extending the idea to a larger class of optical systems such as light pulses in a fibre. Tiny pulses or blobs of coherent, superfast-moving polaritons can be created in space and overlap with one another in a nonlinear way, due to the matter component of polaritons.

“We found the key ingredient is how you couple the pulses with each other,” said Stroev. “If you get the coupling and light intensity right, the light multiplies, affecting the phases of the individual pulses, giving away the answer to the problem. This makes it possible to use light to solve nonlinear problems.”

̽��ֱ��multiplication of the wave functions to determine the phase of the light signal in each element of these optical systems comes from the nonlinearity that occurs naturally or is externally introduced into the system.

“What came as a surprise is that there is no need to project the continuous light phases onto ‘0’ and ‘1’ states necessary for solving problems in binary variables,” said Stroev. “Instead, the system tends to bring about these states at the end of its search for the minimum energy configuration. This is the property that comes from multiplying the light signals. On the contrary, previous optical machines require resonant excitation that fixes the phases to binary values externally.”

̽��ֱ��authors have also suggested and implemented a way to guide the system trajectories towards the solution by temporarily changing the coupling strengths of the signals.

“We should start identifying different classes of problems that can be solved directly by a dedicated physical processor,” said Berloff, who also holds a position at Skolkovo Institute of Science and Technology. “Higher-order binary optimisation problems are one such class, and optical systems can be made very efficient in solving them.”

There are still many challenges to be met before optical computing can demonstrate its superiority in solving hard problems in comparison with modern electronic computers: noise reduction, error correction, improved scalability, guiding the system to the true best solution are among them.

“Changing our framework to directly address different types of problems may bring optical computing machines closer to solving real-world problems that cannot be solved by classical computers,” said Berloff.

Reference:
Nikita Stroev and Natalia G. Berloff. ‘Discrete Polynomial Optimization with Coherent Networks of Condensates and Complex Coupling Switching.’ Physical Review Letters (2021). DOI: 10.1103/PhysRevLett.126.050504

New type of optical computing could solve highly complex problems that are out of reach for even the most powerful supercomputers.

Gleb Berloff, Hills Road Sixth Form College

Artist's impression of light pulses inside an optical computer

Yes

Cambridge researchers awarded European Research Council funding

cg605 — Wed, 09 Dec 2020 17:14:16 +0000

Three hundred and twenty-seven mid-career researchers were today awarded Consolidator Grants by the ERC, totalling €655 million. ̽��ֱ��UK has 50 grantees in this year’s funding round. ̽��ֱ��funding is part of the EU’s current research and innovation programme, Horizon 2020.

̽��ֱ��ERC Consolidator Grants are awarded to outstanding researchers of any nationality and age, with at least seven and up to 12 years of experience after PhD, and a scientific track record showing great promise.

̽��ֱ��research projects proposed by the new grantees cover a wide range of topics in physical sciences and engineering, life sciences, as well as social sciences and humanities.

From the ̽��ֱ�� of Cambridge, the following researchers were named as grantees: Professor Vasco Carvalho, Professor Tuomas Knowles, Dr Neel Krishnaswami, Professor Silvia Vignolini and Dr Kaisey Mandel.

Vasco Carvalho, Professor of Macroeconomics and Director of Cambridge-INET, Faculty of Economics

Project title: Micro Structure and Macro Outcomes.

What is your research about?

“Research under the project MICRO2MACRO takes as a starting point the organisation of production around supply chain networks and, within these networks, the increasing dominance of very large and central firms. This renders a small number of firms and technologies systemic in that they can influence aggregate economic performance.

“Within this broad agenda, MICRO2MACRO explores issues surrounding, first, market power and pro-competitive policies and, second, innovation, productivity and the diffusion of new technologies. ̽��ֱ��project also partners with one global financial institution to unlock relevant real-time, highly granular data that is necessary to study some of these questions.”

How do you feel about being named a grantee?

“I'm ecstatic. First, because it recognises the combined effort of colleagues around the world in developing a new micro-to-macro research agenda and understanding macroeconomic developments via a new lens. Second, because it provides the opportunity to inject otherwise scarce resources into early career researchers and PhD students, thereby adding to the human capital in this research area. Third, because it further highlights a decade of collective efforts at the Faculty of Economics here at Cambridge and helps ensure its continued growth as a hub for the development of new approaches to decades old questions in economics.”

Professor Tuomas Knowles, Yusuf Hamied Department of Chemistry

Project title: Digital Protein Biophysics of Aggregation.

What is your research about?

“Our work is focused on understanding the basic molecular principles that govern the activity of proteins in health and disease. In particular we are interested in how proteins come together to form machinery and compartments that underpin the functions of a living cell, and what happens when these processes fail.

“ ̽��ֱ��ERC project is focused on understanding how proteins condense together to form functional liquid organelles, and how such compartments can gel and form irreversible protein aggregates associated with disease. Such problems have been challenging to study previously due to the very high heterogeneity of the structures that are formed which make observation by conventional bulk techniques challenging. We will be developing new single molecule approaches to study this phenomenon aggregate by aggregate and cell by cell, and in this way shed light on the connection between the physical and structural properties of protein assemblies and their biological activity.”

How do you feel about being named a grantee?

“I am truly delighted by this support of my research and that of my group, which will allow us to develop fundamentally new approaches for probing a process at the core of biological function and malfunction.”

Dr Neel Krishnaswami, Computer Laboratory

Project title: Foundations of Type Inference for Modern Programming Languages.

What is your research about?

“Many modern programming languages, whether industrial or academic, are typed. Each phrase in a program is classified by its type (for example, as strings or integers), and at compile-time programs are checked for consistent usage of types, in a process called type-checking. Thus, the expression ‘3 + 4’ will be accepted, since the + operator takes two numbers as arguments, but the expression ‘3 + ‘hello’’ will be rejected, as it makes no sense to add a number and a string. Though this is a simple idea, sophisticated type systems can track properties like algorithmic complexity and program correctness.

“In general, programmers must write annotations to tell computers which types to check. In theory, it is easy to demand enough annotations to trivialize type-checking, but this can easily make the annotation larger than the program itself! So, to transfer results from formal calculi to real programming languages, we need type inference algorithms, which reconstruct missing types from partially-annotated programs.

“In TypeFoundry, we will use recent developments in proof theory and formal semantics to identify the theoretical structure underpinning type inference.”

How do you feel about being named a grantee?

“Naturally, I am happy to find out that my research is valued in such concrete, material terms, and I'm delighted to have the opportunity to have the chance to support PhD students and postdocs working in this area. I also feel this shows off the best international character of science. I am an Indian-American researcher working in the UK, judged and funded by my European peers. Consequently, I keenly feel both the opportunity and responsibility to carry on the cosmopolitan tradition of scientific work.”

Professor Silvia Vignolini, Yusuf Hamied Department of Chemistry

Project title: Sym-Bionic Matter: developing symbiotic relationships for light-matter interaction.

What is your research about?

“With this ERC grant I aim to develop new platforms and tools to study how different organisms build symbiotic interactions for light management and ‘evolve’ new symbiotic relationships, in which one of the organisms is replaced by an artificial material to generate a novel class of hybrid which I link to call ‘sym-BIonic matTEr’ – BiTe!”

How do you feel about being named a grantee?

“I was very excited to learn that I had been awarded an ERC grant and I look forward to starting the project. It’s an amazing opportunity for my team and me!

“When you receive the evaluation response, you get an email notification that invites you to log into the EU portal to see the outcome of the evaluation. In those few minutes that it takes to open the right form on the platform, I experienced pure panic! When I finally open the letter, I had to read it three times to convince myself that I had been awarded the grant! It was a great day!”

Dr Kaisey Mandel, Institute of Astronomy, Statistical Laboratory of the Department of Pure Mathematics and Mathematical Statistics, Kavli Institute for Cosmology

Project title: Next-Generation Data-Driven Probabilistic Modelling of Type Ia Supernova SEDs in the Optical to Near-Infrared for Robust Cosmological Inference.

What is your research about?

“My research focuses on utilising exploding stars called Type Ia supernovae to measure cosmological distances for tracing the history of cosmic expansion.

“I lead a project to develop state-of-the-art statistical models and advanced, data-driven techniques for analysing observations of these supernovae in optical and near-infrared light to determine more precise and accurate distances.

“Applying these novel methods to supernova data from the Hubble Space Telescope, new ground-based surveys, and, in the near future, the Vera Rubin Observatory's Legacy Survey of Space and Time, we will pursue new and improved constraints on the accelerating expansion of the Universe and the nature of dark energy.”

Five researchers at the ̽��ֱ�� of Cambridge have won consolidator grants from the European Research Council (ERC), Europe’s premiere funding organisation for frontier research.

iStock.com/ BarrySheene

Yes

Squeezing light inside memory devices could help improve performance

sc604 — Mon, 05 Oct 2020 15:00:00 +0000

̽��ֱ��team, led by the ̽��ֱ�� of Cambridge, used the technique to investigate the materials used in random access memories, while in operation. ̽��ֱ��results, reported in the journal Nature Electronics, will allow detailed study of these materials, which are used in memory devices.

̽��ֱ��ability to understand how structural changes characterise the function of these materials, which are used for low-power, ultra-responsive devices called memristors, is important to improve their performance. However, looking inside the 3D nanoscale devices is difficult using traditional techniques.

To solve this issue, the researchers had to reliably construct cavities only a few billionths of a metre across – small enough to trap light within the device. They used the tiny gap between a gold nanoparticle and a mirror and observed how the light was modified when the device was functioning correctly or breaking down.

Using this technique, the researchers were able to observe changes in the colour of the light scattered from the device inner regions when few atomic defects and tiny oxygen bubbles were forming. This enabled them to identify the device breaking mechanism over multiple cycles.

“This work is a big advance in using light to show how materials behave when inside active devices,” said Dr Giuliana Di Martino from Cambridge’s Department of Materials Science and Metallurgy, who led the research. “ ̽��ֱ��strange physics of light interacting with matter on the nanoscale allows us to characterise these devices in real time, where their functioning depends on how the material behaves in a space just a few atoms across. This way, we can reveal the breakdown mechanisms upon cycling and open up new routes for device optimisation towards large-scale technology applications.”

Gaining understanding into the factors determining device failure mechanisms is a fundamental prerequisite for developing energy-efficient and better-performing memory devices, an essential goal for enabling a competitive, data driven economy and driving business innovation through digital transformation and the Internet of Things.

̽��ֱ��research is funded as part of a UK Engineering and Physical Sciences Research Council (EPSRC), the Winton Programme for the Physics of Sustainability and the Royal Academy of Engineering.

Reference:
Di Martino et al. ‘Real-Time In-Situ Optical Tracking of Oxygen Vacancy Migration in Memristors.’ Nature Electronics (2020). DOI: 10.1038/s41928-020-00478-5

Researchers have developed a method to ‘squeeze’ visible light in order to see inside tiny memory devices. ̽��ֱ��technique will allow researchers to probe how these devices break down and how their performance can be improved for a range of applications.

Giuliana Di Martino

Squeezing light

Yes

Computational modelling explains why blues and greens are brightest colours in nature

sc604 — Thu, 10 Sep 2020 23:01:01 +0000

̽��ֱ��researchers, from the ̽��ֱ�� of Cambridge, used a numerical experiment to determine the limits of matt structural colour – a phenomenon which is responsible for some of the most intense colours in nature – and found that it extends only as far as blue and green in the visible spectrum. ̽��ֱ��results, published in PNAS, could be useful in the development of non-toxic paints or coatings with intense colour that never fades.

Structural colour, which is seen in some bird feathers, butterfly wings or insects, is not caused by pigments or dyes, but internal structure alone. ̽��ֱ��appearance of the colour, whether matt or iridescent, will depending on how the structures are arranged at the nanoscale.

Ordered, or crystalline, structures result in iridescent colours, which change when viewed from different angles. Disordered, or correlated, structures result in angle-independent matt colours, which look the same from any viewing angle. Since structural colour does not fade, these angle-independent matt colours would be highly useful for applications such as paints or coatings, where metallic effects are not wanted.

“In addition to their intensity and resistance to fading, a matt paint which uses structural colour would also be far more environmentally-friendly, as toxic dyes and pigments would not be needed,” said first author Gianni Jacucci from Cambridge’s Department of Chemistry. “However, we first need to understand what the limitations are for recreating these types of colours before any commercial applications are possible.”

“Most of the examples of structural colour in nature are iridescent – so far, examples of naturally-occurring matt structural colour only exist in blue or green hues,” said co-author Lukas Schertel. “When we’ve tried to artificially recreate matt structural colour for reds or oranges, we end up with a poor-quality result, both in terms of saturation and colour purity.”

̽��ֱ��researchers, who are based in the lab of Dr Silvia Vignolini, used numerical modelling to determine the limitations of creating saturated, pure and matt red structural colour.

̽��ֱ��researchers modelled the optical response and colour appearance of nanostructures, as found in the natural world. They found that saturated, matt structural colours cannot be recreated in the red region of the visible spectrum, which might explain the absence of these hues in natural systems.

“Because of the complex interplay between single scattering and multiple scattering, and contributions from correlated scattering, we found that in addition to red, yellow and orange can also hardly be reached,” said Vignolini.

Despite the apparent limitations of structural colour, the researchers say these can be overcome by using other kinds of nanostructures, such as network structures or multi-layered hierarchical structures, although these systems are not fully understood yet.

Reference:
Gianni Jacucci et al. ‘ ̽��ֱ��limitations of extending nature’s colour palette in correlated, disordered systems.’ PNAS (2020). DOI: 10.1073/pnas.2010486117

Researchers have shown why intense, pure red colours in nature are mainly produced by pigments, instead of the structural colour that produces bright blue and green hues.

In addition to their intensity and resistance to fading, a matt paint which uses structural colour would also be far more environmentally-friendly, as toxic dyes and pigments would not be needed

Gianni Jacucci

will zhang from Pixabay

Macaw

Yes