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Information transmission

New findings could revolutionize information transmission

A team of researchers at the University of California led by physicists have observed, characterized and controlled dark trions in a semiconductor named tungsten diselenide  (WSe2) which is a feat that could increase the capacity and the form of information transmission. The study has been published in the Physical Review Letters.

In semiconductors like WSe2, a trion is a quantum bound state containing three charged particles. A negative trion has two electrons and one hole whereas a positive trion contains two holes and one electron. A hole is a vacancy in a semiconductor and behaves like a positively charged particle and a trion having 3 interacting particles can carry much more information than a single electron can carry. Electronics today use a single electron to conduct electricity and transmit information. However, trions have a net electric charge and they can be controlled with the help of an electric field. It is possible to control their motion and thus use as an information carrier. In addition to it, they also have controllable spin, momentum and a rich internal structure which can be used to encode information.

On the basis of spin configuration, they can be configured as dark trions and bright trions. A hole and electron in opposite spins are bright trions whereas hole and electron in the same configuration are called dark trions. Bright trions can couple to light strongly and can emit light efficiently means they decay quickly and dark trions couple weakly to light and they decay much more slowly as compared to bright trions. It has a life close to 100 times longer than bright trions and enables transmission of information over a longer distance.

Chun Hung, an assistant professor of physics and astronomy at UC Riverside says that we can allow writing and reading of trion information by light and that they can generate bright and dark trions and control the information that we can encode. Using dark trions for their long life we can realize the information transmission by trions as it allows more information transfer than an individual electron.

They used a single layer of WSe2 atoms like a graphite sheet because dark trions energy level in WSe2 lies below the energy level of bright trions.  The dark trions can, therefore, accumulate a large population, enabling their detection. Lui explains that most of the trion research groups focus on bright trions because they emit light which can be measured.

However, researchers here have a focus on dark trions and how they behave under charge conditions in WSe2 device. They managed to demonstrate the continuous tuning from positive dark trions to negative dark trions by adjusting external voltage and confirm the dark trions by distinct spin configuration from bright trions. Our technology will be greatly enriched by using trions for information transmission. The researchers intend to demonstrate the first prototype using dark trions.

Qubits in quantum computing

Scientists find gravity as key to optimal quantum computation

Scientists have been trying persistently to achieve significant success in the field of Quantum Computing but still, there is a huge scope of improvement if we go by the consensus.

But recently the arduous efforts of all the involved scientists have given them something to cheer at, as there is a claim that gravity a natural phenomenon which has been studied extensively will provide the pathway through which in-depth knowledge of quantum computing can be obtained. The scientific community is hailing these findings because there is a belief that quantum computing will bring a drastic change in the power and scale of computation. The study has been published in Physical Review Letters

The reason behind this linkage between gravity and quantum computing are the geometric rules which are used for finding the shortest distance between two points on a curved surface with respect to gravity in General Relativity. Those same geometric rules can be used for finding the most effective methods to process information in quantum computing.

These points of shortest travel – whether across a spherical planet or inside a quantum computing system – are known as geodesics. A noteworthy point regarding this discovery is that it involves a branch of quantum computing which is conformal field theory. Through this new study, there is a possibility of faster calculations in the above-mentioned branch of quantum computing.

Physicist Pawel Caputa who was involved in this discovery expounds that the process of finding minimal length on complexity geometry is equivalent to solving equations of gravity. So this explanation has made it transparent about how gravity is linked to discovery of quantum computing.

Looking at the other side, there is still a requirement where the reduction of error rates should take place. Along with this, scientists are looking to bring down the interference which hinders the computation process. The reason why quantum computing is thought as the future of computing because it functions on the concept of qubits which is also another form of information. The striking feature of a qubit is its ability to represent several states in contrast to binary digits which have only two states (0 and 1).

Therefore, along with this discovery, recent progress has made quantum computing to be more space efficient and significant improvement in accuracy has taken

All of this promises a bright future for the quantum computing field but the finding has been limited and thus it requires much deeper research which will help in finding its multidisciplinary applications.