More than ten years ago the author described a parameter $K(\rho )$ for the complexity of $n$-qubit quantum state $\rho$ and raised the conjecture (referred to as "Conjecture C") that when this parameter is superpolynomial in $n$, the state $\rho$ is not experimentally feasible (and will not be experimentally achieved without quantum fault-tolerance). Shortly afterward [6] (arXiv:1204.3404), Steve Flammia and Aram Harrow claimed that the simple easy-to-construct $W$ states are counterexamples to "Conjecture C." We point out that Flammia and Harrow's argument regarding $W$-states is incomplete. Moreover, the emergent picture from experimental progress of the past decade on noisy intermediate scale quantum (NISQ) computers suggests that $W$-states, as simple as they appear, cannot be achieved experimentally by NISQ computers, and can not be constructed without quantum fault-tolerance.
翻译:10多年前,作者描述了一个以美元当量子量子的复杂度为单位的参数$K(rho)$(美元 ), 并提出了一个推测(称为“jecture C ” ), 即当该参数以美元计为超极性时, 美元是不可能实验的( 并且不会在没有量子过大的情况下实验地实现 ) 。 之后不久, (6) ( ariv:1204.3404 ), Steve Flammia和Aram Harrow声称简单易建的美元州是“ jecture C”的反例。 我们指出, Flammia和Harrow关于美元状况的论断是不完整的。 此外,过去10年关于超声中型量子计算机实验性进展的浮现图显示,尽管看起来简单,但美元不能由新谢克计算机实验性地达到,而且不能在没有量子过错容忍的情况下建造。