标题： 在共形场理论中的测量诱导纠缠 显示英文标题

标题： Measurement-Induced Entanglement in Conformal Field Theory

摘要： 局部测量可以彻底重塑多体纠缠的模式，尤其是在长程纠缠的量子临界态中。 然而，针对测量对多体态的影响的解析结果仍然很少，测量通常被近似为强制特定的测量结果。 我们研究了汤川-卢廷液态中的测量诱导纠缠（MIE），这是一个由紧凑自由玻色共形场理论（CFT）在低能下描述的1+1维量子临界态的广泛家族。 通过测量局部电荷算符，我们表明MIE是完全普遍的、符合共形不变性的，并且取决于CFT的算符内容。 使用复制技巧来处理测量结果的随机性，我们精确计算了汤川-卢廷液态中的MIE，与矩阵乘积态计算结果非常吻合。 我们表明，物理量子测量的MIE与强制测量结果引起的纠缠有根本的不同，并且在共形不变边界条件的Born平均下有自然的解释。 显示英文摘要

摘要： Local measurements can radically reshape patterns of many-body entanglement, especially in long-range entangled quantum-critical states. Yet, analytical results addressing the effects of measurements on many-body states remain scarce, and measurements are often approximated as forcing specific measurement outcomes. We study measurement-induced entanglement (MIE) in Tomonaga-Luttinger liquids, a broad family of 1+1d quantum critical states described at low energies by compact free boson conformal field theories (CFT). Measuring the local charge operator, we show that the MIE is entirely universal, conformally invariant, and depends on the operator content of the CFT. Using a replica-trick to address the randomness of the measurement outcomes, we compute the MIE exactly for Tomonaga-Luttinger liquids, in very good agreement with matrix-product state calculations. We show that the MIE for physical quantum measurements is fundamentally different from the entanglement induced by forcing measurement outcomes, and has a natural interpretation in terms of Born averaging over conformally-invariant boundary conditions.