论文标题
读取近期量子计算机的重新平衡
Readout Rebalancing for Near Term Quantum Computers
论文作者
论文摘要
读出误差是近期中级量表量子计算机的重要噪声来源。当应该为0时，将量子误认为是1时，比将量子误认为是0时的频率要少得多。当它应该是1时，我们可以通过在执行测量之前应用目标X门来提高量子计算机的读数保真度。放置这些X大门，以便将1个状态的预期Qubit数量最小化。经典的后处理可以消除X门的效果，以使任何可观察到的可观察到的期望值不变。我们表明，使用读数重新平衡时，读数错误更正后的统计不确定性较小。统计优势是电路和计算机依赖性的，可用于$ W $状态，Grover搜索和高斯州。当统计精度中的益处最为明显（在某些情况下几乎是两倍），而在激发状态中有许多量子位的状态具有很高的概率。
Readout errors are a significant source of noise for near term intermediate scale quantum computers. Mismeasuring a qubit as a 1 when it should be 0 occurs much less often than mismeasuring a qubit as a 0 when it should have been 1. We make the simple observation that one can improve the readout fidelity of quantum computers by applying targeted X gates prior to performing a measurement. These X gates are placed so that the expected number of qubits in the 1 state is minimized. Classical post processing can undo the effect of the X gates so that the expectation value of any observable is unchanged. We show that the statistical uncertainty following readout error corrections is smaller when using readout rebalancing. The statistical advantage is circuit- and computer-dependent, and is demonstrated for the $W$ state, a Grover search, and for a Gaussian state. The benefit in statistical precision is most pronounced (and nearly a factor of two in some cases) when states with many qubits in the excited state have high probability.
