# Explained: What Is ‘Quantum Supremacy’?

Technical websites and theoretical computer-science news outlets were buzzing after a story in the U.K.-based Financial Times reported that claims by Google of having achieved ‘quantum supremacy’. The report elaborated that researchers at Google had successfully solved a really difficult problem with the help of quantum computers within seconds which a supercomputer could not. The research paper which included researchers from the National Aeronautics and Space Administration (NASA) will soon be available in a complete form.

**What Are Quantum Computers?**

Quantum computers work differently from the standard computers we work on today. Take advantage of the principles of quantum mechanics, they can easily resolve computational problems that may be tough for the classical computer as the size of the numbers and number of inputs involved grows larger. Quantum computers resemble the air-conditioned server rooms in many offices. The world’s most powerful supercomputer at present can juggle 148,000 trillion operations in a second and requires about 9000 IBM CPUs connected in a particular combination to achieve this. While conventional computers process information in ‘bits’ of 1s and 0s, on at a time under classical physics, quantum computers compute in ‘qubits’ or quantum bits. They exploit the properties of quantum mechanics governing matter on the atomic scale in which processors can be a 1 and a 0 simultaneously i.e. in a state of quantum superposition. As this accelerates the speed of computation, a machine with less than a 100 qubits can solve problems with an amount of data that is even theoretically beyond the capabilities of the most powerful supercomputers. Because of quantum superposition, a quantum computer could probably mimic several classical computers working in parallel. The ideas leading to quantum computers have been around since the 1990s but actual machines were designed after 2011, most remarkably built by Canadian company D-Wave Systems.

**How Will It Help Us?**

Classical supercomputers are limited in speed and capability by energy requirements and also need more physical space. The search for really useful information by processing huge amounts of data swiftly is a real-world problem that can be tackled faster by quantum computers with reduced processors and reduced energy.

**What Quantum Computing Means For Your Bank Accounts And Smartphones**

In theory, a quantum computer can solve problems quickly because it can attack complex problems that are beyond the scope of a classical computer. The elementary advantage is speed as it can simulate several classical computers working in parallel. Quite a few encryption systems used in banking and security applications are premised on the inability of computers to handle mathematical problems that are computationally demanding beyond a limit. In theory, quantum computers can surpass those limits.

**What Has Google Achieved?**

Quantum supremacy denotes that quantum computers are able to solve a problem that a classical computer cannot. In the research paper that stirred the IT community, Google utilized a 53-qubit processor to generate a sequence of millions of numbers. Even though these numbers appeared to be randomly generated, they all conformed to an algorithm generated by Google. A classical supercomputer checked some of these values and found them correct. Google’s quantum computer, called Sycamore, claimed ‘supremacy’ because it reportedly completed the task in just 200 seconds that would apparently have taken a supercomputer 10,000 years to complete.

**Is This An Important Achievement?**

Thought it is definitely impressive, experts warn that this does not infer that the quantum computer can now solve every challenging problem thrown at it. The number-generating task was comparable to a race between a Ferrari and a truck and declaring victory that the Ferrari could do everything that a truck did. While IBM and a few other private institutions have their own quantum computer prototypes, they have their own unique inclination to errors making them incapable of executing real-world problems as supercomputers.

There is also a possibility that the creation of completely new mathematical methods or techniques would allow classical computers to execute the same task faster. Some experts even oppose the term ‘quantum supremacy’ coined by theoretical physicist John Preskill of the California Institute of Technology, United States. But the Google achievement shows that quantum computers are capable of a real-world task and gives confidence to private entrepreneurs and academics to invest time and funds to improving and customizing them to real-world problems.

In terms of the number of qubits, D-Wave Systems states it is ready to commercially launch a 5000-qubit system by 2020. NASA already has its 1000-qubit system. D-Wave claims that popular car maker Volkswagen used its quantum computers to work out how best to regulate a fleet of taxis in Beijing relying on data from 10,000 cars. But their research paper on this experiment does not clearly explain how the proposed solution is better than algorithms that are presently used to optimize traffic flow.

**What Will It Mean For Online Banking?**

Breaking banking grade encryption is not within reach as of now. Scott Aaronson, a theoretical computer scientist who has written on Google’s accomplishment, opines that existing encryption standards would require a quantum computer with “several thousand logical qubits” working in tandem flawlessly. It requires millions of specific qubits that powers Sycamore to make ‘logical qubits’ and the 53 available at Sycamore are not sufficient.

Soo, there may be other approaches to designing quantum computers and with cleverer ways to solve problems using them. Moreover, if technological breakthroughs posed a real threat to banking or financial operations, it is to be expected that banks will themselves harness quantum computers.