Establishing EPR-channels between Nanomechanics and Atomic Ensembles

Einstein-Podolsky-Rosen Entanglement between Separated Atomic Ensembles

The Einstein-Podolsky-Rosen (EPR) entanglement is of special importance not only for fundamental research in quantum mechanics, but also for quantum information processing. Establishing EPR entanglement between two memory systems, such as atomic ensembles, nitrogen-vacancy centers, and rare-earth-ion-doped solids is promising for realizing spatial-multimode based quantum communication, quantum computation, and quantum imaging. To date, there have been few reports on realizing EPR entanglement between physical systems in true position and momentum. Here we describe successfully establishing suc…

Einstein-Podolsky-Rosen entanglement and asymmetric steering between distant macroscopic mechanical and magnonic systems

We propose a deterministic scheme for establishing hybrid Einstein-Podolsky-Rosen (EPR) entanglement channel between a macroscopic mechanical oscillator and a magnon mode in a distant yttrium-iron-garnet (YIG) sphere across about ten gigahertz of frequency difference. The system consists of a driven electromechanical cavity which is unidirectionally coupled to a distant electromagnonical cavity inside which a YIG sphere is placed. We find that far beyond the sideband-resolved regime in the electromechanical subsystem, stationary phonon-magnon EPR entanglement can be achieved. This is realized …

Sudden death and revival of Gaussian Einstein-Podolsky-Rosen steering in noisy channels

Einstein-Podolsky-Rosen (EPR) steering is a useful resource for secure quantum information tasks. It is crucial to investigate the effect of inevitable loss and noise in quantum channels on EPR steering. We analyze and experimentally demonstrate the influence of purity of quantum states and excess noise on Gaussian EPR steering by distributing a two-mode squeezed state through lossy and noisy channels, respectively. We show that the impurity of state never leads to sudden death of Gaussian EPR steering, but the noise in quantum channel can. Then we revive the disappeared Gaussian EPR steering …

复合量子电磁感应透明热机与纳米机械镜耦合的提案

Proposal for Composite Quantum Electromagnetically Induced Transparency Heat Engine Coupled by a Nanomechanical Mirror

本文提出一种由超冷原子气体与纳米机械镜耦合的量子热机模型，通过镜面振动产生光机械边带影响输出，并设计了三种配置，发现振动会降低三能级热机亮度但复合热机略有增强，且偏离理想热机特性。

Quantum discord is Bohr's notion of non-mechanical disturbance introduced in his answer to EPR

By rigorously formalizing the Einstein-Podolsky-Rosen (EPR) argument, and Bohr's reply, one can appreciate that both arguments were technically correct. Their opposed conclusions about the completeness of quantum mechanics hinged upon an explicit difference in their criteria for when a measurement on Alice's system can be regarded as not disturbing Bob's system. The EPR criteria allow their conclusion (incompletness) to be reached by establishing the physical reality of just a single observable $q$ (not a conjugate pair $q$ and $p$), but I show that Bohr's definition of disturbance prevents th…

含YIG球的双拉盖尔-高斯腔光力学中两个旋转反射镜的高斯几何失谐、纠缠与EPR操控

Gaussian geometric discord, entanglement and EPR-steering of two rotational mirrors in a double Laguerre-Gaussian cavity optomechanics in the presence of YIG sphere

提出含YIG球的双拉盖尔-高斯腔光力学方案，系统分析两个旋转反射镜的稳态纠缠、GGD与单向/双向EPR操控及其参数和热噪声影响。