There are many digital devices around us regularly, based on the work of — silicon and semiconductor microcircuits. However, their productivity growth rates regularly slow down, requiring the use of new materials. The rapid development of the Internet of Things, artificial intelligence, robotics, 6G networks and quantum computers is forcing manufacturers to look for alternative ways to improve the efficiency of devices. In this article, we examined the reasons for the gradual withdrawal from silicon and possible materials that can replace it in various fields..
Reaching the performance limit
We live in an era of digital technology based on computer circuits that process electronic signals. Nowadays, they usually consist of silicon, which is a semiconductor and is excellent for solving various problems. In 1965, Intel co-founder Gordon Moore noticed a pattern whereby each year the number of transistors per unit of chip area doubled and production costs were cut in half. A modern smartphone contains over 200 billion transistors. The so-called Moore’s law worked successfully for 50 years, but now the dynamics of development is slowing down.
The doubling period is already 1.5 years and continues to increase.
This means that silicon chips are approaching the performance limit due to lagging behind the current growth in demand for higher processing speed, light sensitivity and lower latency. Although we are not talking about replacing silicon anytime soon. The researchers say that until 2025, efficiency will be correlated with Moore’s Law. Until 2040, silicon will dominate the market, and possibly even later will be partially used in digital systems..
Chips generate heat as they work, so researchers are exploring superconductivity, new cooling, and quantum mechanics to create alternative computations. Now productivity is increased by cooling equipment to extremely low temperatures, but this method will bring 4–10 additional years of scalable power and memory.
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Next-generation semiconductors are made from two or more chemical elements, making them faster and more efficient. For example, gallium nitride outperforms silicon in terms of speed (100 times), sensitivity to light and radiation, making it attractive for technologies such as 6G and self-driving vehicles..
Such materials are already beginning to be used, and in the future they will lead to a revolution in the Internet of Things industry. Stephen Doran, CEO of UK-based Compound Semiconductor Application Catapult, says complex semiconductors will impact IoT in the same way the Internet does communication..
Many have heard of the unique physical properties of graphene, carbon tubes and similar materials. They consist of one or more layers of atoms connected to form a crystal lattice. In addition to their high strength, they have enormous thermal and electrical conductivity, which makes them very promising for the nanoelectronics of the future..
Recent research has found that graphene has a unique principle of transferring and storing electrical charge in its atomic lattice. However, it will take years to change technologies, since now this direction is mainly developing in research laboratories, and their production is slow and expensive. Although silicon devices also took decades of research to reach a sufficient industrial level.
Scientists are now talking about single atoms as separate elements of future devices. In existing storage devices, 1 bit occupies about 100 thousand atoms, which provides a significant margin for further improvement of data storage methods..
A team of French scientists from the EPFL Institute of Physics recently conducted a successful experiment in this area. They proved that information on individual magnetized atoms can not only be written down, but also removed by changing the temperature. This makes it possible to re-record it.
Scientists from the University of Alberta have presented a data storage technology based on the manipulation of individual hydrogen atoms. IBM researchers have also demonstrated a similar way of storing data on a single base unit of substance..
David Harold, vice president of marketing communications at Imagination Technologies, says that individual atoms are inherently less resilient than large structures, leading to an increased risk of information loss and corruption. Therefore, additional methods of error control and correction will be required, which scientists are already working on..
In addition to classical computer systems, quantum ones are actively developing, which use the principles of superposition and entanglement of elementary particles. However, unlike bit ones, their work is based on qubits. They usually use photons to compute and transmit information. In addition to the need to maintain a state of uncertainty, they are sensitive to external influences and very unstable. Therefore, the classical methods of data exchange are not suitable.
Several groups of researchers believe that diamonds will help in solving these problems. Scientists at Harvard and Cambridge have created ultra-thin diamond strings with various impurities that can be used to create a quantum Internet or increase the storage time of qubits’ information. A team from the Netherlands has presented a similar project and plans to create a network between institutes in four cities of the country in the next few years..
Physicists at Princeton University have discovered that silicon-vacancy diamonds emit photons at a fixed frequency, which could also be used to create a quantum internet. Although such a system can last forever, enormous pressure is required to achieve the required radiation level..
A group of physicists from the University of Central Florida discovered that more than one electronic model can exist in the structure of the compressed Hf2Te2P matter. The presence of several quantum properties at once makes it possible to use it for the transfer and storage of energy at the subatomic level..
D-Wave presented a model of a three-dimensional superconducting material capable of changing properties under the influence of a magnetic field, including disordered phases. This feature will allow it to be used to create microcircuits for quantum computers..
It has been known for a long time about the existence of temporal crystals, which are capable of changing under the influence of external energy influences. They have an internal «fluid» structure and constantly undergo spontaneous internal transformations, which makes them promising materials.
Scientists at the University of Sussex recently developed a way to manipulate liquid metal. They say that in the future they will be able to program the material to perform certain actions. In addition to increasing the possibilities in the field of electrical conductivity, it can increase the functionality of digital devices, allowing them to change their shape, size and structure within the existing volume..
It is impossible to speak with absolute certainty about the displacement of silicon. Stephen Doran says this is unlikely to happen anytime soon, perhaps never. It is also impossible to accurately predict the future, but, most likely, computer systems will consist of several layers of technologies that compensate for each other’s shortcomings. Nevertheless, experts expect an end to the trend of exponential growth in computing power without new breakthroughs in this area..
text: Ivan Malichenko, photo: Tyler Lastovich / Unsplash, Yellowcloud, Dagesyan Sarkis, Hustvedt, Maria Delaney / Wikimedia Commons, Steve Jurvetson / Flickr