According to the article published in the Nature Communications journal, American physicists have discovered the method of boosting graphene superconduction properties while studying the material’s carbon and calcium monatomic layers.
Thus, physicists have been able to turn graphene into super-fast ‘highway’ for electrons, ‘With this brand-new technique we have managed to demonstrate how electrons in graphene layers form into Cooper pairs, which in turn provides superconductivity, as well as highlights the role of calcium layers. Now we can claim that we understand the nature of superconductivity in graphene fully’, Jonathan Sobota from Stanford University says.
Sobota and his colleagues said that they were able to uncover the secret of superconductivity for graphene and find several methods for practical implementation, due to a thorough research of the graphene sandwich structure and ultrathin calcium sheets through applying a synchrotron SSRL emitter in SLAC National Accelerator Laboratory at Stanford.
As noted by the authors, physicists around the world are well aware of graphene and calcium sandwiches superconducting properties for almost 10 years. In recent years, scientists have tried to reproduce this property in pure graphene as well as in a range of other materials; however, the attempts resulted in a failure due to lack of understanding on superconductivity nature.
Sobota group has resolved this problem, by lighting up the pieces of graphite and calcium sheets using X-ray appliances, which helped them understand how electrons move within these sandwich and how the so-called Cooper pairs are formed within the material that provide superconductivity .
Graphene Vision Unlocked
A group of researchers from the University of Michigan, headed by a seasoned electrical engineer Zhaohui Zhong, has found a way to create tiny imagers that do not require refrigeration. The brand-new technology utilises graphene and, in fact, represents an infrared camera of a fingernail size. Compared to the current cumbersome thermal imaging devices, the technology is fairly considered to be a major breakthrough in miniaturisation field.
It’s a common knowledge that graphene is capable of perceiving infrared radiation at room temperature. Unfortunately, the sensitivity of graphene IR sensors was pretty low (100-1000 less than a commercial device requires) until now, and that was the cause of inability to produce an electrical signal, sufficient for an imager.
To resolve this problem, the researchers decided to abandon the conventional technology of the optical sensor when the infrared light falls on graphene, releases electrons, which in their turn create an electronic signal. Instead, the inventors decided to analyze how the light-induced electric charges applied to the upper graphene layer affect the current flowing through the lower layer. Thus, the scientists have combined together two layers of graphene: the lower layer missed electric current, while the top one began to irradiate infrared light. It turned out that under the influence of infrared radiation, electrons leave positively charged holes in graphene’s upper layer. These holes contribute to the emergence of an electric field which affects the flow of electrons in the lower layer of graphene. Therefore, basing on the oscillation parameters measurement technology of the current in the lower layer, it is possible to create ultra IR sensor.
Given the latest achievements, an extremely compact infrared sensor based on graphene can accommodate even on the surface of the contact lens. In the presence of savvy graphene companies, such as 2-DTECH or Graphene Technologies, promoting graphene uses to make benefits from innovations, there is no doubt that the technology will enter the mass production if the trials are a success.
According to the developers, the new IR sensor has the same sensitivity in the mid-IR range as modern thermal imagers. Taking in account it doesn’t require efficient cooling it can be used in mobile phones, glasses and even contact lenses.