论文标题
全息测量和批量传送
Holographic measurement and bulk teleportation
论文作者
论文摘要
全息图告诉我们,时空是紧急的,其特性取决于双重理论的纠缠结构。在本文中,我们描述了边界理论的子区域$ a $ a $ a $ a的纠缠变化如何修改散装双时空。我们发现,LPM摧毁了部分几何形状,从而产生了计量后的散装空间双重双重偶数,并在互补的未测量区域$ a^c $上得到了世界末日的branes。使用$ ADS_3 $中的批量计算和全息图的张量网络模型,我们表明,在测量之后保留的散装几何形状的部分取决于$ a $的大小以及我们投射到的状态。测量后的散装双二至$ a^c $包括最初是在测量之前$ a $的纠缠楔的区域。这表明在边界子区域上执行的LPM $ a $ teleport部分最初以$ a $编码的互补区域$ a^c $编码。在半经典全息图中,可以通过这种方式传送任意数量的大量信息,而在张量网络模型中,传送的信息受到$ a $ a $ a $ a^c $之间的纠缠数量的上限,这是有限的 - $ n $效果。当$ a $是两个不相交子区域的联合时,测量值会触发其余两个未衡量的子区域之间的纠缠/分离相变,与批量描述中的连接/断开相变相对应。我们的结果为测量对全息理论的纠缠结构的影响提供了新的启示,并深入了解了如何从边界理论中操纵批量信息。它们也可以扩展到更通用的量子系统并进行实验测试,并代表了迈向测量引起的相变的全息描述的第一步。
Holography has taught us that spacetime is emergent and its properties depend on the entanglement structure of the dual theory. In this paper, we describe how changes in the entanglement due to a local projective measurement (LPM) on a subregion $A$ of the boundary theory modify the bulk dual spacetime. We find that LPMs destroy portions of the bulk geometry, yielding post-measurement bulk spacetimes dual to the complementary unmeasured region $A^c$ that are cut off by end-of-the-world branes. Using a bulk calculation in $AdS_3$ and tensor network models of holography, we show that the portions of the bulk geometry that are preserved after the measurement depend on the size of $A$ and the state we project onto. The post-measurement bulk dual to $A^c$ includes regions that were originally part of the entanglement wedge of $A$ prior to measurement. This suggests that LPMs performed on a boundary subregion $A$ teleport part of the bulk information originally encoded in $A$ into the complementary region $A^c$. In semiclassical holography an arbitrary amount of bulk information can be teleported in this way, while in tensor network models the teleported information is upper-bounded by the amount of entanglement shared between $A$ and $A^c$ due to finite-$N$ effects. When $A$ is the union of two disjoint subregions, the measurement triggers an entangled/disentangled phase transition between the remaining two unmeasured subregions, corresponding to a connected/disconnected phase transition in the bulk description. Our results shed new light on the effects of measurement on the entanglement structure of holographic theories and give insight on how bulk information can be manipulated from the boundary theory. They could also be extended to more general quantum systems and tested experimentally, and represent a first step towards a holographic description of measurement-induced phase transitions.