论文标题
使用Zeno效应的多量量子门
A Multi-Qubit Quantum Gate Using the Zeno Effect
论文作者
论文摘要
ZENO效应重复观测冻结了量子系统的动力学，它是量子力学的标志性奇数。当测量无法区分子空间中的状态时，该子空间内的动力学可以深刻改变，从而导致非平凡的行为。在这里，我们表明，这样的测量可以将仅具有单量控控制的非相互作用系统变成两个或多Qubit的纠缠门，我们称之为Zeno Gate。该栅极通过在系统上赋予几何阶段的几何阶段来起作用，该阶段位于特定的非本地子空间内。我们在许多非理想性下得出了栅极保真度的简单闭合形式表达式，并表明该栅极对于在电路和腔QED系统中实现是可行的。更具体地说，我们在马尔可夫和非马克维亚读数方面通过分散读数说明了门的功能，并得出了纵向读数的条件，以理想地实现门。
The Zeno effect, in which repeated observation freezes the dynamics of a quantum system, stands as an iconic oddity of quantum mechanics. When a measurement is unable to distinguish between states in a subspace, the dynamics within that subspace can be profoundly altered, leading to non-trivial behavior. Here we show that such a measurement can turn a non-interacting system with only single-qubit control into a two- or multi-qubit entangling gate, which we call a Zeno gate. The gate works by imparting a geometric phase on the system, conditioned on it lying within a particular nonlocal subspace. We derive simple closed-form expressions for the gate fidelity under a number of non-idealities and show that the gate is viable for implementation in circuit and cavity QED systems. More specifically, we illustrate the functioning of the gate via dispersive readout in both the Markovian and non-Markovian readout regimes, and derive conditions for longitudinal readout to ideally realize the gate.
