论文标题
纯种量子状态
Pure dephasing of magnonic quantum states
论文作者
论文摘要
对于最近提出和证明的广泛的非经典镁质状态，除镁质寿命外，新的时间尺度（木元素脱舌时）变得很重要，但是很少研究这个时间尺度。考虑到交换相互作用和自旋 - 音波耦合，我们评估了纯木元素的时间，发现在几个kelvins的温度下它比少量寿命小。通过以镁猫状态为例，我们表明了镁的纯粹脱落是如何摧毁量子叠加的生存的。因此，在纯dephasing时间内执行量子操作至关重要。我们进一步得出了描述纯dephasing的作用的密度矩阵的主方程，该方法可以推广其方法，包括将来实验可能会遇到的其他dephasing通道。我们的发现使人们能够设计和操纵强大的镁量子状态，以进行信息处理。
For a wide range of nonclassical magnonic states that have been proposed and demonstrated recently, a new time scale besides the magnon lifetime - the magnon dephasing time - becomes important, but this time scale is rarely studied. Considering exchange interaction and spin-phonon coupling, we evaluate the pure magnon dephasing time and find it to be smaller than the magnon lifetime at temperatures of a few Kelvins. By examining a magnonic cat state as an example, we show how pure dephasing of magnons destroys and limits the survival of quantum superpositions. Thus it will be critical to perform quantum operations within the pure dephasing time. We further derive the master equation for the density matrix describing such magnonic quantum states taking into account the role of pure dephasing, whose methodology can be generalized to include additional dephasing channels that experiments are likely to encounter in the future. Our findings enable one to design and manipulate robust quantum states of magnons for information processing.
