The race for quantum computing between Google, IBM, and Intel is at its peak. Google is leading the race as it just unveiled Bristlecone, a new quantum computer chip with the record-setting power of 72 quantum bits (qubits). Normal computers operate in binary and data is represented as zeros or ones. But, in quantum mechanics a qubit can be in a superposition of both, representing both a zero and a one at the same time. This results in an exponential increase of power in quantum computing.
This nifty feature allows quantum computers capable of performing different operations simultaneously whereas a classic computer has to run through each in turn. This would mean that a quantum computer made with a 49-qubit chip could very well outperform our current best supercomputers.
Bristlecone, Google’s latest prototype has massive 72 qubits arranged in a square array and they get their quantum nature through superconductivity. This allows them to represent multiple states by conducting current in two different directions at once.
Qubits are very sensitive and fragile and even a slight fluctuation can cause memory errors that can jeopardize the whole calculation. These fluctuations can be hard to detect which makes the whole thing very tricky. This is great for quantum encryption system as they alert you if someone tries to hack in but problematic when you simply want to read the output of a quantum computer.
Google Quantum AI Lab developed a quantum error correction (QEC) technique and demonstrated it in a nine qubit system. The Google team is now trying to implement the same system on the Bristlecone processor. They test the system by deliberately introducing a single error in the system and then compare the results with those of a classical computer.
The team is hopeful that Bristlecone should be able to minimize error to a negligible amount eventually and when it does, it will easily outperform a supercomputer and will become the building block for larger scale quantum computers.