Researchers at Google’s Quantum Artificial Intelligence Lab have proposed a law that, if true, will bring powerful quantum computers into existence by the end of this year. The hypothesis, known as Neven’s Law after Hartmut Neven, the Director of the lab, could represent the start of quantum computing.
What Is Neven’s Law?
Neven’s Law is a term used to refer to a rule regarding the advancement of quantum computers. The law states that quantum computers are increasing in power at a ‘doubly exponential’ rate, as stated by Neven at the Google Quantum Spring Symposium in May this year.
The well-known Moore’s law predicted that classical computing will grow to twice its size approximately every two years. While the general increase in computing power has slowed down, manufacturers are finding ways to increase computing power on their chips.
Even for its rapid growth, Moore’s Law is still an exponential increase. This means that computing power grows by a power of 2, in the sense of 21, 22, 23, 24. Neven’s Law, on the other hand, is a double exponential growth.
This means that any future improvements will increase computing power by a factor of a power of power of 2. This kind of growth is highly uncommon in nature and result in a rapid growth considering other factors are taken care of.
The reason for this double exponential growth is due to two reasons. The first is that Google itself is decreasing the rate of error in its quantum processors, allowing for larger quantum processors to be built.
The second is that quantum processors are inherently exponentially better than classical processors. This is due to the fact that quantum computers do not function on bits, but on qubits instead.
What Makes Quantum Computers Better?
Computers today function on binary bases. All calculations that they conduct occur in either 1 or 0, and this is the base on which modern computing is built. In quantum computers, qubits are used to perform the calculations, and they can be both 1 and 0 at the same time.
This means that they will be doubly efficient as traditional computers, as they will provide double the computing power, increasing exponentially. For example, something that takes a normal computer 4 bits to do only requires 2 qubits, 16-bit operations require only 4 qubits.
This exponential growth, combined with the exponential growth of the processors themselves, creates an environment wherein the computing power of classical computers seems to be falling behind.
However, it is also to be noted that classical computing is not standing still. Quite to the contrary, hitting a roadblock on making processors smaller has only caused innovation in the form of newer architectures and algorithms for effective processing. The advancement of classical computing is also not a slouch, as computers get faster with every passing year.
The ‘law’ itself is based on an assumption of what Google was able to achieve within a year. The team has been seeing quick advancements in the scale of the processors they can build at their facility. Late last year, their best processor functioned at the same level as a laptop. Today, special time needs to be taken on Google’s Cloud computing platform to test the quantum processor against.
This has created a rapidly growing ecosystem in the quantum space; one that Neven says will result in quantum computing by the end of 2019.
The Race for Quantum Supremacy
These advancements are taking place in order to get quantum computers to reach a processing level more than the world’s most powerful classical supercomputer. This phenomenon is known as quantum supremacy and represents the moment when problems cannot be solved by classical computers, but can be solved by quantum ones.
There are also many companies participating in the space at this point in time, including giants such as IBM, Intel and Google. These companies are engaging with quantum computing on a huge scale, creating subdivisions for the cutting edge in research.
Google has been especially vocal about their requirement to reach quantum supremacy, and has predicted in the past that they will reach the goal soon. This seems to be their most concrete effort until date, seeing the quick advancement of their processors.
In addition to fast advancement, Google stands to gain from the rise of quantum computing. Upon developing dependable interface methods, it is possible to run machine learning and AI tasks on the computer for AI training like never before.
However, it is important to note that there are various engineering problems associated with creating a quantum computer. Primary among them is noise, the aforementioned errors in the quantum computing process.
India has also risen to prominence in the quantum computing state, as they have invested over ₹80 crore to efforts in quantum computing. Researchers in institutes such as the Indian Institute of Science Education and Research have also ran tests on low-powered quantum computing processors.
Sceptics of quantum computing state that it is not possible to reduce noise without reducing the processing power of a computer. With noise, the possibility of qubit corruption is high. In addition to noise, existing computer support architecture will have to be rebuilt from the ground up to ensure that quantum computers work flawlessly.
If companies can get through these challenges, it is very much possible that quantum computers can represent the next big step in computing the big problems of the world.