Nanophotonics and nano-optics
Short description
We study interaction of light with various materials at the nanoscale via nanoantennas, and apply this knowledge in creating novel optical metamaterials and metadevices, light-operated information processing and storage, actively-controlled photochemistry and sustainable energy management.
Optical Tellegen metamaterial
Researchers from the Nanophotonics and nano-optics group, jointly with researchers Aalto University (Finland), University of Pennsylvania (USA) and Stanford University (USA) theoretically proposed to create a kind of metamaterial that has been beyond the reach of existing technologies so far. Unlike natural materials, metamaterials can be structurally tailored to have specific properties, meaning scientists can create materials with features on demand.
The new metamaterial takes advantage of the so called nonreciprocal magnetoelectric (NME) effect. The NME effect (also called Tellegen effect) implies a link between specific properties of the material (its magnetization and optical polarization) and the different components of an electromagnetic wave. The NME effect is negligible in natural materials, but scientists have been trying to enhance it using metamaterials because of the technological potential this would unlock.
Magnetic storage that runs on light
Researchers at the Department of Physics have carried out projects to make magnetic storage operate with light, making it more energy efficient, smaller, and about 10 000 times faster than what is currently available.
鈥淭o achieve this, we take the primely efficient light concentrators, optical nanoantennas, and make them channel light to the nanoscale, where we put magnetic materials,鈥 says Alexandre Dmitriev, professor at the Department of Physics.
News items
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A pulse of light makes polaritons disappear (July 2023)
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Light, electrons and energy in the mix (March 2023)
- Ultrafast energy-efficient magnetic memory goes brain-like (December 2022)
- Magnetic storage that runs on light (December 2021)
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Nano-carpets of gold
We contribute to the Gothenburg 91探花 Festival 2020 with the entry Nano-carpets of gold
"This is an electron microscope image of polymer micro-balls, packed on a surface, covered/wrapped by a thin (10 nanometers) carbon film with gold nano-dots / gold dust (100 nm size) on top. The carbon film itself is actually invisible in the picture. This nanofabrication method, allowing us to wrap and cover things at the nanoscale 鈥 just like in real macro-life 鈥 was developed by researchers at Chalmers and University 91探花.
If we can wrap small things, we can protect or add extra functions to them. Wrapping live bacteria this way might help extract all kinds of information from their surface. This could for example be used for bacterial diagnostics 鈥 like putting thousands of little sensors on the 鈥榖east鈥.
Invisible carbon carpets might also work as membranes in catalysis, since they are very porous. Then the dots are the catalysts, designed to speed up selected chemical reactions when gas flows through them. Since we can stack hundreds of such membranes together, we can save lots of energy on producing various chemical compounds. It can potentially make the production of chemicals 鈥榞reener鈥 by letting us use less environmentally harmful catalysts."
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FEMTOTERABYTE
We finished coordinating our massive EU Horizon2020 FET-Open project FEMTOTERABYTE 鈥楽pinoptical nanoantenna-assisted magnetic storage at few nanometers on femtosecond timescale鈥, aiming at magnetic hard drives that are 100 times smaller and 10,000 times faster than the ones we use today.
Solariton
Our spin-off project on solar nano-thermal windows taking part in VentureCup Sweden Start-Up 2020. We use nanoantennas on regular glass windows to make them warm-up using sunlight. The glass stays transparent and doesn鈥檛 change the color of the sunlight, it is color-neutral. Solariton was a Chalmers School of Entrepreneurship project in 2019-2020.
More highlights
- A new PhD project jointly with In猫s Massiot鈥檚 group at LAAS-CNRS in Toulouse, France, on saving the planet with nanoantennas and thermoelectro-photovoltaics.
- Reading magnetic molecules as the future ultimate memory units. News piece: Magnetic discovery paves the way for molecular memories
- Collaborative project on .
- Public invited lecture within the IDEAS seminar series at the Danish institute for Advanced Studies (DEAS), University of Southern Denmark (SDU), "".
Future ultrafast and energy-efficient magnetic memory
With the exponential increase for the data cloud storage needs - we envision the magnetic storage of the future to 鈥榬un on light鈥, i.e., read/write with light, be more energy-efficient, much smaller and about 10 000 times faster than what鈥檚 currently available. To achieve that, we concentrate the femtosecond pulses of light by optical nanoantennas combined with magnets.
Magnetism in non-magnetic materials
We reveal magnetically tunable optical effect in a special kind of artificial materials, called hyperbolic metamaterials, displaying nontrivial optical properties, such as conductive behaviour along particular spatial directions and insulating behaviour along others. This is a possible step towards future magnetically-controlled optics.
Nanoscale magnetophotonics
Everything you need to know about science & tech of light + magnetism at the nanoscale in our massive (open) .
Nanoscale chiral chemistry
Possible future of nanoscale chiral chemistry 鈥 on our recent
Single-molecules magnets
For the first time, the studies of single-molecules magnets go out of the large synchrotron facilities, as the ultra-sensitive detection of the magnetic properties of just a few monolayers of the molecular magnets can now be studied with conventional optical magnetic circular dichroism, strongly enhanced by the nanoantennas. This opens the long-envisioned path towards using single-molecule magnets as the ultimate atom-sized memory units.
Melting gold
How to melt gold at room temperature at the atomic scale:
Optically chiral polarizing transparent surface
We devised optically chiral polarizing transparent surface that can be changed in real time by more than 100% with the externally applied low magnetic field. Future directions include the tunable lenses, on-chip beam-steering (for example, for FaceID light sources), dynamic holograms and other exciting optical functionalities.
Ultra-thin single-crystalline silicon solar cell
In a large EU (FET-Open) project collaboration, we conceived an ultra-thin (effective thickness about 800 nanometers) single-crystalline silicon solar cell with the efficiency of 9.6%. For comparison 鈥 conventional crystalline Si solar cells measure 200 microns in thickness and have the efficiency of slightly above 20%. The prospects are open for the highly efficient and semi-transparent solar cells.
This work is featured in the .
Nanoplasmonic biological and chemical sensing
Building on the magnetoplasmonic sensing principles, established in our previous works, we pushed the limits of detection and the figure-of-merit of nanoplasmonic biological and chemical sensing several orders of magnitude.