Extends the lifetime of atoms using a mirror
Researchers at Chalmers University of Technology have succeeded in an experiment where they get an artificial atom to survive ten times longer than normal by positioning the atom in front of a mirror. The findings were recently published in the journal Nature Physics.
If we add energy to an atom, we say that the atom is excited, and it normally takes some time before the atom loses energy and returns to its original state. This time is called the lifetime of the atom. Chalmers’ researchers have placed an artificial atom at a specific distance in front of a mirror. By changing the distance to the mirror, they can get the atom to live longer, up to 10 times as long as if the mirror had not been there.
Spin lifetime of electrons in graphene increased by magnetic fields
Researchers at Chalmers University of Technology shows that applying a moderate in-plane magnetic field increases spin lifetime of electrons in graphene. The results of this work have profound implications for graphene’s use as post-CMOS platform in spintronics, and make an important contribution to the understanding of physics of 2D materials. The findings have recently been published in the prestigious journal Physical Review Letters.
Graphene-based film can be used for efficient cooling of electronics
Researchers at Chalmers University of Technology have developed a method for efficiently cooling of electronics using graphene-based film. The film has a thermal conductivity capacity that is four times that of copper. Besides, the graphene film is attachable to electronic components made of silicon, which favours the film’s performance compared to typical graphene characteristics shown in previous, similar experiments.
New nano-scale processing technology paves the road for using carbon nanotubes in flexible and stretchable electronics
Research scientists at Department of Microtechnology and Nanosciences, Chalmers University of Technology have recently developed a new large scale method to functionalize carbon nanotubes (CNTs). This makes it potentially possible for utilizing CNTs as interconnect material for flexible and stretchable electronics products.
Graphene looking promising for future spintronic devices
Researchers at Chalmers University of Technology have discovered that large area graphene is able to preserve electron spin over an extended period, and communicate it over greater distances than had previously been known. This has opened the door for the development of spintronics, with an aim to manufacturing faster and more energy-efficient memory and processors in computers.
The findings are published in the journal Nature Communications.
“We believe that these results will attract a lot of attention in the research community and put graphene on the map for applications in spintronic components,” says Saroj Dash, who leads the research group at Chalmers University of Technology.
The sound of an atom has been captured
Researchers at Chalmers are first to show the use of sound to communicate with an artificial atom. They can thereby demonstrate phenomena from quantum physics with sound taking on the role of light. The interaction between atoms and light is well known and has been studied extensively in the field of quantum optics. However, to achieve the same kind of interaction with sound waves has been a more challenging undertaking. The Chalmers researchers have now succeeded in making acoustic waves couple to an artificial atom. The study was done in collaboration between experimental and theoretical physicists.
Noise in a microwave amplifier is limited by quantum particles of heat
In a collaboration with Caltech and University of Salamanca, researchers at Chalmers published a paper in Nature Materials on how device self-heating limits the noise temperature reduction when cooling the InP HEMT transistor towards zero Kelvin. This was highlighted in a press release from both Chalmers and Caltech. Furthermore, the researchers have characterised InP HEMTs at room and cryogenic temperatures by pulsed measurements. The results indicated the role of material defects in the InAlAs-InGaAs-InP heterostructure responsible for the enhanced kink effects in the transistor DC output characteristics under cryogenic conditions.
Graphene provides efficient electronics cooling
A layer of graphene can reduce the working temperature in hotspots inside a processor by up to 25 percent – which can significantly extend the working life of computers and other electronics. An international group of researchers, headed by researchers at MC2, are the first in the world to show that graphene has a heat dissipating effect on silicon based electronics. The research has been undertaken in partnership with the Hong Kong University of Science and Technology, Shanghai University and the Swedish company SHT Smart High Tech AB.
Spin inside silicon devices
A strong interest in silicon based spintronic devices stems from the expected long spin coherence length and its industrial importance. However, implementing spin functionalities in silicon, and understanding the fundamental processes of spin transport and manipulation remain the main challenges. Researchers at Chalmers demonstrated large spin polarisations in silicon at room temperature, 34% in n-type and 10% in p-type silicon, using a narrow Schottky and a thin SiO2 tunnel barrier in a direct tunneling regime. Furthermore, by increasing the width of the Schottky barrier in non-degenerate Si, they observed a drastic change in the spin injection and detection processes. These studies provide a deeper insight into the spin transport phenomenon, which should be considered for electrical spin injection into any semiconductor.
Terahertz sensor aiming for Jupiter´s moons
A high performance terahertz receiver aiming for space missions such as ESA’s “Jupiter icy moons explorer” has been developed in a joint European effort, led by researchers at MC2 in collaboration with Omnisys Instruments. “The unique sensor is compact, light-weight, robust and operates at room temperature, a necessity for satellite missions requiring many years of operation” says professor Jan Stake at MC2, Chalmers.
Cooled integrated circuit amplifies with lowest noise so far
Researchers at MC2 in collaboration with Low Noise Factory have demonstrated an integrated amplifier with the lowest noise performance so far. The 0.5-13 GHz wide-band design exhibited a high gain over 38 dB across the band and an ultra-low noise figure of 0.045 dB. The amplifier offers new possibilities for detecting the faintest electromagnetic radiation, for example from distant galaxies.
Advanced brain investigations can become better and cheaper
An important method for brain research and diagnosis is magnetoencephalography (MEG). But the MEG systems are so expensive that not all EU countries have one today. A group of researchers at Chalmers University of Technology are now showing that MEG can be performed with technology that is significantly cheaper than that which is used today – technology that can furthermore provide new knowledge about the brain. Communication between brain cells generates magnetic fields that can be measured with SQUID sensors. Focal MEG puts the sensors closer to the head, thereby improving signal levels and enhancing focus on brain activity.
Quantum microphone captures extremely weak sound
Scientists from Chalmers University of Technology have demonstrated a new kind of detector for sound at the level of quietness of quantum mechanics. The result offers prospects of a new class of quantum hybrid circuits that mix acoustic elements with electrical ones, and may help illuminate new phenomena of quantum physics.
Graphene mixer can speed up future electronics
Researchers at Chalmers University of Technology have for the first time demonstrated a novel subharmonic graphene FET mixer at microwave frequencies. The mixer provides new opportunities in future electronics, as it enables compact circuit technology, potential to reach high frequencies and integration with silicon technology.
Rapid laser for harsh environments
Researchers at Chalmers University of Technology have reached a data rate of 40 Gbit/s at a temperature of 85 º C through on-going development of their already world-leading technology for fast data communication lasers. This is a breakthrough in the quest for fast lasers for optical communication links in harsh environments such as data centres and supercomputers, where temperatures can reach high levels, while large amounts of data must be transferred between routers, servers, switches, processors and memories.
Chalmers scientists create light from vacuum
Scientists at Chalmers have succeeded in creating light from vacuum – observing an effect first predicted over 40 years ago. The results have been published in the journal Nature. In an innovative experiment, the scientists have managed to capture some of the photons that are constantly appearing and disappearing in the vacuum. In the Chalmers scientists’ experiments, virtual photons bounce off a “mirror” that vibrates at a speed that is almost as high as the speed of light. The round mirror in the picture is a symbol, and under that is the quantum electronic component (referred to as a SQUID), which acts as a mirror. This makes real photons appear (in pairs) in vacuum.