✍Surbhi Dinesh Singh Khichi

Google's Willow, the so called State-of- the- art quantum computing chip is here. And the secret is, it can solve a problem in simply five minutes which might take the fastest supercomputer on Earth ten septillion years. 10,000,000,000,000,000,000,000,000 years, can you believe it? This is much longer than the age of the universe. It's not that we care whether the supercomputer is faster or the quantum chip? What we are after is the quantum computing? Why the whole world is running after the quantum computers? Before discussing about the quantum computers, firstly let us understand what is Willow really and how does it works.

Know all about Google’s Willow –

The problem chosen while revealing the quantum chip was an RCS, which stands for Random Circuit Sampling. This Google’s chip has 105 qubits which is just a tiny portion of the largest quantum processors. Willow could achieve two major achievements. To which, Hartmut Neven, the Founder and Lead of Google Quantum AI shares, “The first is that Willow can reduce errors exponentially as we scale up using more qubits. This cracks a key challenge in quantum error correction that the field has pursued for almost 30 years. Second, Willow performed a standard benchmark computation that took five minutes.”

Willow is a major achievement for Google Quantum AI that was founded in 2012. It is a major breakthrough working towards building large scale quantum computers, which will be able to solve the unsolvable. Earlier before, Google launched the first chip Foxtail in 2017, Bristlecone in 2018 and Sycamore in 2019. Overcoming various challenges, with Willow there is an increase in quantum coherence times (5x, I.e. 100 microseconds). The qubits in Willow operate below the quantum error correction threshold, suppressing the errors. As explained by Julian Kelly, Director of Quantum Hardware, “The errors rates are halved each time we add physical qubits and scale from distance 3 to 5 to 7 surface codes.” Moreover, if the number of qubits is increased in the quantum chips making them complex, the quantum error correction will improve their accuracy.

The chip’s components are single and two qubit gates, qubit reset and readout engineered and integrated so that there is no lag between any two components, otherwise the system performance gets affected. Willow has the best in class performance across the two benchmarks of quantum error correction and random circuit sampling.

This is all about Willow, the chip in your hand. But do you really know about the desktop you sit on every day, how does the machine works? And how is a quantum computer different from it?

The Traditional OR Classical computer v/s Quantum computer-

Well, the differential gap between a traditional computer and a super computer has widened over time. And today, we can spot a huge difference.

First, let us talk about a traditional computer. A typical traditional computer works in the form of BITS which is a value of either 0 or 1. All the words and numbers that you input to a computer gets translated into it in the binary code of 0 and 1. A binary code is the machine readable language that is only understood by the computer. But the output received is again in the human readable form.

For quantum computers, it’s not the binary digits, it is the qubits. Qubits are not 1 or 0; they are rather complex. They are in waves, where a 0 means a lower energy wave and a 1 means a higher energy wave. It’s not that it would be a 0 or 1, but each qubit has the probability of being the other, per say, there can be a 75% probability of having a value of 1 and a 25% probability of having a value of 0. You will come across a single qubit representing a larger amount of information than a single bit can. When a quantum computer is working, there is an interaction of a multiple qubits. The probabilities are altered while running an algorithm. The world’s largest quantum processor is the IBM’s quantum computer which was first unveiled in 2021, which is made up of 433 qubits

A quantum computer can solve what traditional computer cannot. It can process information and find structure in tons of data, which is not at all possible for a traditional computer.

Now, as you have read the comparison, you should skip on to knowing what can quantum computing do? Will it change the world dynamics?

What can a fully functional Quantum computer really do?

Unreliability of Encryption – A quantum computer when fully functional has code breaking capabilities, that can result into making all forms of online encryption unreliable. RSA is a public key encryption algorithm upon which all the transactions on the Internet are conducted, all the encryption schemes worldwide work, be it the digital certificates, digital signatures or the email encryption.

The RSA is based on a discrete logarithm problem. If the RSA goes, the encryption also breaks. American mathematician Peter Shor developed the Shor’s algorithm which can give the factors and prime factors of very large numbers. Now, by using his algorithm, if we scale up the quantum computer to a certain level, it can possibly break the discrete logarithm problem. Thus, breaking down anything in an encrypted form, also a cryptocurrency like Bitcoin. But for that, there is time. Until we develop one with massive number of qubits.

Simulating of nature – Nature, the environment around us works on the law of quantum physics, the molecular space. The atomic structure is based upon quantum physics. Quantum computers can help in building batteries, designing new materials for electronics, renewable energy and energy storage basically everything that has a long chain of molecules. Weather forecasting, studying complex weather patterns, while in healthcare, sequencing and analyzing a person’s genes.

Fuel up Artificial Intelligence -  Very soon, we will be able to see driverless cars on streets. This can be possible because of AI, when charged up by a quantum computer. When it comes to an AI model, a quantum computer can compute the large number of data needed. The training data for AI models will be easily accessible to a quantum computer. The AI game can be on a roll very soon.

These are the reasons why the world is after Quantum computers. Why now with Google, a new pathway has opened. It has been rightly said, the next world war would be a data war, a digital war. And the fight will go in the favor of the one who masters quantum computing. Yes, AI is the future but the one that trains the model behind, imagine how powerful that would be. The game of cubits shall bring the world to its knees. Of course, it has time now, but Willow has ensured that Quantum computers are more early than soon.