Why haven’t we got useful quantum computers yet?

Quantum computer systems have lengthy promised to unravel sure issues quicker than any extraordinary, or classical, pc can. In reality, Google delivered on this promise in 2019, when it declared that its quantum computer had achieved quantum supremacy, performing a calculation inconceivable for one of the best classical computer systems of the day. As New Scientist mentioned on the time, Google had “secured yet another place in the history books”.

But the subsequent chapter of the quantum revolution is struggling to be written. Since …