论文标题
量子自然重力的空间量子纠缠见证人
Spatial Qubit Entanglement Witness for Quantum Natured Gravity
论文作者
论文摘要
最近提出了通过两个肿块的纠缠来证明重力的量子性质。使用Qubits见证这种纠缠的建议可以使两个群众足够接近，以使完整的1/R相互作用正在发挥作用（而不是其二阶泰勒扩张），而微米尺寸的质量则由10-100微米（有或没有电磁筛选）隔开，足以提供0.01-1-1 Hz的生长速率。然而，到目前为止，提出的唯一可行的方法是使用嵌入在群众中的旋转，其相关性用于见证干涉时间过程中群众之间发生的纠缠。这带来了双重挑战，即将旋转相干性的方法结合到协议中，以及对控制场的苛刻精确度，以准确完成自旋（stern-gerlach）干涉法。在这里，我们表明，如果可以创建每个质量的不同空间定位状态的叠加，无论是什么手段，单独的简单位置相关测量都可以产生群众之间纠缠的空间Qubit见证人。我们发现，在协议的特定阶段进行大量挤压是主要的新要求（除需要维持空间量子相干性的需求之外），以实现其可行性
Evidencing the quantum nature of gravity through the entanglement of two masses has recently been proposed. Proposals using qubits to witness this entanglement can afford to bring two masses close enough so that the complete 1/r interaction is at play (as opposed to its second-order Taylor expansion), and micron-sized masses separated by 10-100 microns (with or without electromagnetic screening) suffice to provide a 0.01-1 Hz rate of growth of entanglement. Yet the only viable method proposed for obtaining qubit witnesses so far has been to employ spins embedded in the masses, whose correlations are used to witness the entanglement developed between masses during interferometry. This comes with the dual challenge of incorporating spin coherence-preserving methodologies into the protocol, as well as a demanding precision of control fields for the accurate completion of spin-aided (Stern-Gerlach) interferometry. Here we show that if superpositions of distinct spatially localized states of each mass can be created, whatever the means, simple position correlation measurements alone can yield a spatial qubit witness of entanglement between the masses. We find that a significant squeezing at a specific stage of the protocol is the principal new requirement (in addition to the need to maintain spatial quantum coherence) for its viability
