Thus we have invented a way to make a perfect transition between the nanowire and a superconductor.
The superconductor in this case is aluminium. There is great potential in this, "says Associate professor Thomas Sand Jespersen,
which they deposit the superconductor niobium nitride in a pattern useful for photon detection. At both ends of the resulting detector they deposit gold electrodes.
#High-temperature superconductivity in atomically thin films A research group has succeeded in fabricating an atomically thin,
high-temperature superconductor film with a superconducting transition temperature (Tc) of up to 60 K(-213°C). The team also established the method to control/tune the Tc.
This finding not only provides an ideal platform for investigating the mechanism of superconductivity in the two-dimensional system,
because the unique quantum effects in superconductors are a great advantage in achieving the energy saving
the device application of superconductors has long been hindered. The largest obstacle is the necessity of a huge and expensive cooling system with liquid helium, because of the low Tc of conventional superconductors,
which is close to absolute zero (0 K, --273°C)* 1. It has also been a big challenge to realize the high-density integration of superconductors into electronic devices.
In order to overcome these problems, it is definitely necessary to develop a new superconductor with higher-Tc,
that can be fabricated into a thin film. The research team at Tohoku University turned its attention to iron selenide (Fese
which is a member of iron-based superconductors*2 . While the Tc of bulk Fese is only 8 K(-265°C a signature of higher-Tc superconductivity has been suggested in ultrathin film
and its verification has been required urgently. The researchers at first fabricated high-quality, atomically thin Fese films Fig. 1, with thickness of between one monolayer (which corresponds to three-atoms thickness) and twenty monolayers (sixty-atoms thickness),
which is direct evidence of the emergence of superconductivity in the films. The researchers found that the Tc estimated from the gap-closing in a monolayer film is surprisingly high (above 60 K),
While multilayer films do not show superconductivity in the as-grown state, the researchers have discovered a novel method to deposit alkali atoms onto the films
the researchers have succeeded in converting non-superconducting multilayer Fese films into high-Tc superconductors with Tc as high as 50 K. The present result gives a great impact to both the basic
and applied researches in superconductors. The researchers have shown clearly how the superconductivity is emerged, enhanced and controlled in atomically thin Fese films.
While the Tc achieved in this study (50-60 K) is still lower than that of the cuprate high-Tc superconductors (highest Tc?
135 K) which caused the"high-Tc fever"in the world 30 years ago, it obviously exceeds the record of other"high-Tc superconductors"such as fullerene (C60) superconductors (Tc 33 K) and Mgb2 (Tc 39k),
closely approaching the temperature of liquid nitrogen (77 K). The present report would lead to intensive researches to further increase Tc by changing the number of atomic layers, the amount of doped electrons and the species of substrate.
and applied researches on superconductivity, because the Tc of 50-60 K achieved in the present study is high enough to keep the superconducting state by using a closed-cycle-gas-type cooling system without liquid helium.
The present success in fabricating an atomically thin high-temperature superconductor not only provides an ideal platform to investigate the novel two-dimensional superconductivity,
The ultrathin high-Tc superconductor would effectively contribute to the significant downsizing and consequent high-density integration in electric circuits,
said Zhifeng Ren, principal investigator at the Texas Center for Superconductivity at UH (Tcsuh.""This is a form for the quick screening of materials,
The idea was to take a Cooper pair--a pair of electrons that allows electricity to flow freely in superconductors
while tunneling--a quantum phenomenon--across a junction between two superconductor leads, to pass through two separate"quantum dots"--small crystals that have quantum properties."
#Researchers Discover Electron Pairing without Superconductivity A team of physicists from the University of Pittsburgh, the University of Wisconsin-Madison,
Superconductors are used for many applications including in magnetic resonance imaging devices and for magnetic energy storage. The basis for all superconductors is the formation of electron pairs.
In the normal non-superconducting phase, the electrons in most metals move independentlyhe scattering of electrons causes electrical resistance.
In a superconductor, the paired electrons move in a highly coordinated fashion that has zero electrical resistance.
The discovery provides clues about the mechanisms causing superconductivity in strontium titanate, which may eventually help researchers to the discovery of a material that superconducts at room temperature.
advances the understanding and use of complex oxide materials that boast unusual properties such as superconductivity and colossal magnetoresistance but are notoriously difficult to control.
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