摘要
Quantum computing1 promises exponential speed-up in for such tasks as factorizing,simulating many-body quantum systems,and quantum machine learning.However,to achieve such computational speed-up is far from trivial.A universal quantum computer needs at least:(1)many qubits that can be individually coherently controlled;(2)many quantum gates/operations that can establish correlations among many qubits;and(3)fault-tolerance architecture that can correct the errors during computation,and hence output the correct answers.Each of these three requirements is highly demanding to realize.
