Ramping up the qubitsJulian Kelly/GoogleBy Matt ReynoldsGoogle is leading the pack when it comes to quantum computing. The company is testing a 20-qubit processor – its most powerful quantum chip yet – and is on target to have a working 49-qubit chip by the end of this year. Qubits, or quantum bits, can be a mixture of 0 and 1 at the same time, making...