Superconducting quantum computing

Physics

Qubit

Algorithm

Statistical physics

Condensed matter physics

Computer science

Superconductivity

Quantum mechanics

State (computer science)

Quantum

Physical Review Letters

Progress in superconducting qubit experiments with greater numbers of qubits or advanced techniques such as feedback requires faster and more accurate state measurement. We have designed a multiplexed measurement system with a bandpass filter that allows fast measurement without increasing environmental damping of the qubits. We use this to demonstrate simultaneous measurement of four qubits on a single superconducting integrated circuit, the fastest of which can be measured to 99.8% accuracy in 140ns. This accuracy and speed is suitable for advanced multi-qubit experiments including surface code error correction.

Fast Accurate State Measurement with Superconducting Qubits