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Prismor och ljus som bryts.
Photo: Anna-Lena Lundqvist
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Nanophotonics and nano-optics

Research group
Active research
Project owner
Department of Physics

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.

Recent highlights

Tellegen material
Photo: Ihar Faniayeu, University of Gothenburg

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.

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illusration
Photo: Alexandre Dmitriev

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. 

“To achieve this, we take the primely efficient light concentrators, optical nanoantennas, and make them channel light to the nanoscale, where we put magnetic materials,” says Alexandre Dmitriev, professor at the Department of Physics.

News items

Nano-carpets of gold

We contribute to the Gothenburg Science 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 – just like in real macro-life – was developed by researchers at Chalmers and University of Gothenburg.

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Illustration of a nano-carpet of gold

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 – like putting thousands of little sensors on the ‘beast’.

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 ‘greener’ by letting us use less environmentally harmful catalysts."

 

Femtoterabyte logo

FEMTOTERABYTE

We finished coordinating our massive EU Horizon2020 FET-Open project FEMTOTERABYTE ‘Spinoptical nanoantenna-assisted magnetic storage at few nanometers on femtosecond timescale’, aiming at magnetic hard drives that are 100 times smaller and 10,000 times faster than the ones we use today.

Solariton team and logo

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’t change the color of the sunlight, it is color-neutral. Solariton was a Chalmers School of Entrepreneurship project in 2019-2020.

More highlights

Recently pubished advances

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 ‘run on light’, i.e., read/write with light, be more energy-efficient, much smaller and about 10 000 times faster than what’s 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) review of nanoscale magnetophotonics.

Nanoscale chiral chemistry

Possible future of nanoscale chiral chemistry – on our recent open-access Perspective

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.
Article in Materials Horizons

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Illustration of melting gold on the nano scale

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 – 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 Nano Futures Inaugural highlights collection.

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.
News feature at Phys.org