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Last week, IBM said it will build Quantum Condor, a 1121 qubit quantum computer, by the end of 2023. The company claims the system can control behaviour of atoms to run applications, and generate world-changing materials to transform industries. IBM says its full-stack quantum computer can be deployed via cloud, and that it can be programmed from any part of the world.

The technology company is developing a super-fridge, internally codenamed Goldeneye, to house the computer. The 10-foot-tall and 6-foot-wide refrigerator is being designed for a million-qubit system.

What are Qubits and quantum computers?

Quantum computers process data exponentially faster than personal computers do. They deploy non-intuitive methods, coupled with lots of computing, to solve intractable problems. These machines operate using qubits, similar to bits in personal computers.

The similarity ends there. The way quantum machines solve a problem is very different from how a traditional machine does.

A classical computer tries solving a problem intuitively. If they are given a command, they attempt every possible move, one after another, turning back at dead ends, until they find a solution.

Quantum computers deploy superposition to solve problems. This allows them to exist in multiple states, and test all possible ways at once. And qubits, the fundamental units of data in quantum computing, enables these machines to compute this way.

In regular computers, bits have either 0 or 1 value, and they come in four possible combinations - - 00, 01, 10, 11. Only one combination can exist at a single point of time, which limits processing speed.

But, in quantum machines, two qubits can represent same values, and all four can exist at the same time. This helps these systems to run faster.

This means that n qubits can represent 2n states. So, 2 qubits represent 4 states, 3 qubits 8 states, 4 qubits 16 states, and so on. And now imagine the many states IBMs 1121 qubit system can represent.

An ordinary 64-bit computer would take hundred years to cycle through these combinations. And thats exactly why quantum computers are being built: to solve intractable problems and break-down theories that are practically impossible for classical computers.

To make such large and difficult calculations happen, the qubits need to be linked together in quantum entanglement. This enables qubits at any end of the universe to connect and be manipulated in such a way that not one can be described without referencing the others.

Why are qubits difficult?

One of the key challenges for processing in qubits is the possibility of losing data during transition. Additionally, assembling qubits, writing and reading information from them is a difficult task.

The fundamental units demand special attention, including a perfect isolation and a thermostat set of one hundredth of a degree above absolute zero. Despite strict monitoring, due to their highly sensitive nature, they can lose superposition even from a slightest variation. This makes programming very tricky.

Since quantum computers are programmed using a sequence of logic gates of various kinds, programmes need to run quickly before qubits lose coherence. The combination of superposition and entanglement makes this process a whole lot harder.

Other companies building quantum computers

There has been a lot of interest in quantum computing in recent times. In 2016, IBM put the first quantum computer in the cloud. Google launched Sycamore quantum computer last year, and said it was close to achieving quantum supremacy.

This month, IBM released its 65-qubit IBM Quantum Hummingbird processor to IBM Q Network members, and the company is planning to surpass the 100-qubit milestone with its 127-qubit IBM Quantum Eagle processor next year. It is also planning to roll out a 433-qubit IBM Quantum Osprey system in 2022.

D-Wave systems, a Canada-based quantum computing company, launched its cloud service in India and Australia this year. It gives researchers and developers in these two countries real-time access to its quantum computers.

Honeywell recently outlined its quantum system, and other technology companies like Microsoft and Intel are also chasing commercialisation.

The ongoing experiments and analysis speak volumes on how tech companies are viewing quantum computers as the next big breakthrough in computing.

Quantum computers will likely deliver tremendous speed, and will help in solving problems related to optimisation in defence, finance, and other industries.

IBM views the 1000-qubit mark as the point from where the commercialisation of quantum computers can take off.

Excerpt from:
IBM plans to build a 1121 qubit system. What does this technology mean? - The Hindu