Experimental systems with power-law interactions have recently garnered interest as promising platforms for quantum information processing. Such systems are capable of spreading entanglement superballistically and achieving an asymptotic speed-up over locally interacting systems. Recently, protocols developed by Eldredge et al. [Phys. Rev. Lett. 119, 170503 (2017)] and Tran et al. [Phys. Rev. X 11, 031016 (2021)] for the task of transferring a quantum state between distant particles quickly were shown to be optimal and saturate theoretical bounds. However, the implementation of these protocols in physical systems with long-range interactions remains to be fully realized. In this work, we provide an experimental roadmap towards realizing fast state-transfer protocols in three classes of atomic and molecular systems with dipolar interactions: polar molecules composed of alkali-metal dimers, neutral atoms in excited Rydberg states, and atoms with strong magnetic moments (e.g. dysprosium). As a guide to near-term experimental implementation, we numerically evaluate the tradeoffs between the two protocols for small system sizes and develop methods to address potential crosstalk errors that may arise during the execution of the protocols.
Roadmap Towards Quantum Entanglement Positron Emission Tomography (QE-PET)
Institute of Physics, Jagiellonian University（雅盖隆大学物理研究所）；Center for Theranostics, Jagiellonian University（雅盖隆大学诊疗中心）；University of California Santa Cruz（加州大学圣克鲁兹分校）；Indian Institute of Technology Bombay（印度理工学院孟买分校）；The University of Tokyo（东京大学）；Institute for Medical Research and Occupational Health, Division of Radiation Protection（医学研究与职业健康研究所辐射防护部）；University of Sydney（悉尼大学）；University of Zagreb Faculty of Science, Department of Physics（萨格勒布大学理学院物理系）；ICTP South American Institute for Fundamental Research（ICTP南美基础研究所）；Universidade Federal de São Paulo（圣保罗联邦大学）；Instituto de Fisica Corpuscular (IFIC), CSIC-UV（粒子物理研究所（IFIC），西班牙国家研究委员会-瓦伦西亚大学）；University of Illinois Urbana–Champaign（伊利诺伊大学厄巴纳-香槟分校）；National Institutes for Quantum Science and Technology（国立量子科学技术研究院）；Institute of Science Tokyo（东京科学研究所）
Quantum Information Networks (QINs) attract increasing interest, as they enable connecting quantum devices over long distances, thus greatly enhancing their intrinsic computing, sensing, and security capabilities. The core mechanism of a QIN is quantum state teleportation, consuming quantum entanglement, which can be seen in this context as a new kind of network resource. Here we identify use cases per activity sector, including key performance targets, as a reference for the network requirements. We then define a high-level architecture of a generic QIN, before focusing on the architecture of…
Gate-defined quantum dots in gallium arsenide (GaAs) have been used extensively for pioneering spin qubit devices due to the relative simplicity of fabrication and favourable electronic properties such as a single conduction band valley, a small effective mass, and stable dopants. GaAs spin qubits are readily produced in many labs and are currently studied for various applications, including entanglement, quantum non-demolition measurements, automatic tuning, multi-dot arrays, coherent exchange coupling, and teleportation. Even while much attention is shifting to other materials, GaAs devices …
We investigate the chiral quantum walk (CQW) as a mechanism for an entanglement transfer on a triangular chain structure. We specifically consider two-site spatially entangled cases in short-time and long-time regimes. Using the concurrence as an entanglement measure; fidelity, and the Bures distance as the measure of the quality of the state transfer, we evaluate the success of the entanglement transfer. We compare the entangled state transfer time and quality in CQW against a continuous-time quantum random walk. We also observe the effect of mixed states on the entanglement transfer quality.
Quantum computers are promising for simulations of chemical and physical systems, but the limited capabilities of today's quantum processors permit only small, and often approximate, simulations. Here we present a method, classical entanglement forging, that harnesses classical resources to capture quantum correlations and double the size of the system that can be simulated on quantum hardware. Shifting some of the computation to classical post-processing allows us to represent ten spin-orbitals on five qubits of an IBM Quantum processor to compute the ground state energy of the water molecule…
Linear optical quantum computing is beset by the lack of deterministic entangling operations besides photon loss. Motivated by advancements at the experimental front in deterministic generation of various kinds of multiphoton entangled states, we propose an architecture for linear-optical quantum computing that harnesses the availability of three-photon Greenberger-Horne-Zeilinger (GHZ) states. Our architecture and its subvariants use polarized photons in GHZ states, polarization beam splitters, delay lines, optical switches and on-off detectors. We concatenate topological quantum error correc…
Robust entanglement between a movable mirror and atomic ensemble and entanglement transfer in coupled optomechanical system
提出了一种在光机耦合系统中实现可动镜与原子系综宏观纠缠的方案。在实验上可获得的参数制度，我们表明，在我们的计划中的二分连续变量纠缠的临界温度可以从以前的24 K [Vitali { \it et al.}，物理修订信函\textbf{98}，030405（2007）]和20 K [基因{ \it等人}，Phys. Rev. A \textbf{77}，050307（R）（2008）]至32 K。我们还研究了基于这种耦合系统的纠缠转移。该方案可用于实现连续变量量子信息处理和量子极限位移测量的量子存储器。
A quantum interface for two-way entanglement transfer between orbital angular momentum degree of freedom in free space and time-energy degree of freedom in optical fibers, provides a novel way toward establishing entanglement between remote heterogeneous quantum nodes. Here, we experimentally demonstrate this kind of transfer interface by using two interferometric cyclic gates. By using this quantum interface, we perform two-way entanglement transfer for the two degrees of freedom. The results show that the quantum entangled state can be switched back and forth between orbital angular momentum…
Reversible entanglement transfer between light and matter is a crucial requisite for the ongoing developments of quantum information technologies. Quantum networks and their envisioned applications, e.g., secure communications beyond direct transmission, distributed quantum computing or enhanced sensing, rely on entanglement distribution between nodes. Although entanglement transfer has been demonstrated, a current roadblock is the limited efficiency of this process that can compromise the scalability of multi-step architectures. Here we demonstrate the efficient transfer of heralded single-ph…
Minimal energy cost of thermodynamic information processes only with entanglement transfer
我们提出了最小的能量成本的测量和信息擦除，仅使用亥姆霍兹自由能和纠缠的形成。形成的纠缠以差分的形式出现，表示过程中存储器上的纠缠转移量;测量的代价由纠缠增益给出，而信息擦除的代价由可用纠缠的损失给出。将本函和Rev. E 88，042143（2013）放在一起，我们可以仅根据形成的纠缠来描述第二定律的违反和恢复;信息过程热力学对传统热力学第二定律的超额功和信息过程的总代价都由形成纠缠给出，且前者小于或等于后者。
The high probability state transfers and entanglements between different nodes of the homogeneous spin 1/2 chain in inhomogeneous external magnetic field
Quantum communications require efficient implementations of quantum state transportation with high fidelity. Here, we consider the transport of entanglement along a chain of qubits. A series of SWAP operations involving successive pairs of qubits can transport entanglement along the chain. We report that the fidelity of the abovementioned gate has a maximum value corresponding to an optimum value of the drive amplitude in the presence of drive-induced decoherence. To incorporate environmental effect, we use a previously reported fluctuation-regulated quantum master equation [A. Chakrabarti and…
We propose a hybrid cavity magnomechanical system to realize and transfer the bipartite entanglements and Einstein-Podolsky-Rosen (EPR) steerings between magnons, photons, and phonons in the regime of stability of the system. As a parity-time-symmetric-like structure exhibiting the natural magnetostrictive magnon-phonon interaction, our passive-active cavity system can be explored to enhance the robust distant quantum entanglement and generate the relatively obvious asymmetric (even directional) EPR steering that is useful for the task with the highly asymmetric trusts of the bidirectional loc…
