Reversal of the Weak Measurement of a Quantum State in a Superconducting Phase Qubit 论文

详细信息

发表期刊/会议

Physical Review Letters

发表日期

2008-11-10

发表年份

2008

摘要

We demonstrate in a superconducting qubit the conditional recovery (uncollapsing) of a quantum state after a partial-collapse measurement. A weak measurement extracts information and results in a nonunitary transformation of the qubit state. However, by adding a rotation and a second partial measurement with the same strength, we erase the extracted information, canceling the effect of both measurements. The fidelity of the state recovery is measured using quantum process tomography and found to be above 70% for partial-collapse strength less than 0.6.