基于辅助单比特测量的量子态读取算法

A quantum state readout method based on a single ancilla qubit

在量子计算过程中,需要通过量子测量读取计算结果.然而,受限于物理实现,对量子态的测量往往存在较大误差,直接影响量子计算结果的正确提取,以及限制量子计算的大规模扩展.本文针对一种特定形式的量子态,提出基于辅助单比特测量的量子态间接读取算法,避免多比特测量带来的大量测量误差.理论和模拟结果表明,当所读取的量子态比特数较大时,该算法相比于直接读取具有更高的正确率,可用于大规模量子纠错和量子态的高保真度读取.

Quantum state measurement is essential for reading-out a quantum computing outcome.Meanwhile,the readout results are always affected by the large noise of quantum measurements in physical implementation,which also hinders the large-scale expansion of quantum computing.In light of this,we present an indirect quantum state readout method based on a single ancilla qubit that can avoid the large noise of multiple-qubit measurements.The theoretical analysis and simulations indicate that our method is more robust against the measurement noise and promises to become a method of large-scale quantum error correction and high-fidelity quantum state readout.