scholarly journals QUANTUM LOGIC BETWEEN DISTANT TRAPPED IONS

2010 ◽  
Vol 08 (01n02) ◽  
pp. 337-394 ◽  
Author(s):  
S. OLMSCHENK ◽  
D. HAYES ◽  
D. N. MATSUKEVICH ◽  
P. MAUNZ ◽  
D. L. MOEHRING ◽  
...  
Keyword(s):  
Quantum Computation ◽  
Large Scale ◽  
Quantum Communication ◽  
Trapped Ions ◽  
Long Distance ◽  
Detailed Review ◽  
Atomic Ions ◽  
Experimental Implementation ◽  
Unique Path ◽  
Atomic States

Trapped atomic ions have proven to be one of the most promising candidates for the realization of quantum computation due to their long trapping times, excellent coherence properties, and exquisite control of the internal atomic states. Integrating ions (quantum memory) with photons (distance link) offers a unique path to large-scale quantum computation and long-distance quantum communication. In this article, we present a detailed review of the experimental implementation of a heralded photon-mediated quantum gate between remote ions, and the employment of this gate to perform a teleportation protocol between two ions separated by a distance of about one meter.

Scalable trapped ion quantum computation with a probabilistic ion-photon mapping

2004 ◽  
Vol 4 (3) ◽  
pp. 165-173
Author(s):  
L.-M. Duan ◽  
B.B. Blinov ◽  
D.L. Moehring ◽  
C. Monroe
Keyword(s):  
Quantum Computation ◽  
Coulomb Interaction ◽  
Large Scale ◽  
Trapped Ions ◽  
Quantum Gates ◽  
Photon Mapping ◽  
Trapped Ion ◽  
Experimental Noise

We propose a method for scaling trapped ions for large-scale quantum computation and communication based on a probabilistic ion-photon mapping. Deterministic quantum gates between remotely located trapped ions can be achieved through detection of spontaneously-emitted photons, accompanied by the local Coulomb interaction between neighboring ions. We discuss gate speeds and tolerance to experimental noise for different probabilistic entanglement schemes.

scholarly journals Hyper-parallel nonlocal CNOT operation with hyperentanglement assisted by cross-Kerr nonlinearity

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Ping Zhou ◽  
Li Lv
Keyword(s):  
Quantum Computation ◽  
Channel Capacity ◽  
Quantum Channel ◽  
Quantum Communication ◽  
Kerr Nonlinearity ◽  
Spatial Mode ◽  
Cnot Gate ◽  
Long Distance ◽  
Current Technology ◽  
Cnot Operation

Abstract Implementing CNOT operation nonlocally is one of central tasks in distributed quantum computation. Most of previously protocols for implementation quantum CNOT operation only consider implement CNOT operation in one degree of freedom(DOF). In this paper, we present a scheme for nonlocal implementation of hyper-parallel CNOT operation in polarization and spatial-mode DOFs via hyperentanglement. The CNOT operations in polarization DOF and spatial-mode DOF can be remote implemented simultaneously with hyperentanglement assisited by cross-Kerr nonlinearity. Hyper-parallel nonlocal CNOT gate can enhance the quantum channel capacity for distributed quantum computation and long-distance quantum communication. We discuss the experiment feasibility for hyper-parallel nonlocal gate. It shows that the protocol for hyper-parallel nonlocal CNOT operation can be realized with current technology.

scholarly journals One-hour coherent optical storage in an atomic frequency comb memory

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Yu Ma ◽  
You-Zhi Ma ◽  
Zong-Quan Zhou ◽  
Chuan-Feng Li ◽  
Guang-Can Guo
Keyword(s):  
Optical Fibers ◽  
Large Scale ◽  
Quantum Communication ◽  
Frequency Comb ◽  
Quantum Memory ◽  
Spin Coherence ◽  
Quantum Repeater ◽  
Long Distance ◽  
Alternative Solutions ◽  
Atomic Frequency

AbstractPhoton loss in optical fibers prevents long-distance distribution of quantum information on the ground. Quantum repeater is proposed to overcome this problem, but the communication distance is still limited so far because of the system complexity of the quantum repeater scheme. Alternative solutions include transportable quantum memory and quantum-memory-equipped satellites, where long-lived optical quantum memories are the key components to realize global quantum communication. However, the longest storage time of the optical memories demonstrated so far is approximately 1 minute. Here, by employing a zero-first-order-Zeeman magnetic field and dynamical decoupling to protect the spin coherence in a solid, we demonstrate coherent storage of light in an atomic frequency comb memory over 1 hour, leading to a promising future for large-scale quantum communication based on long-lived solid-state quantum memories.

scholarly journals Entangling single atoms over 33 km telecom fibre

2022 ◽  
Author(s):  
Tim van Leent ◽  
Matthias Bock ◽  
Florian Fertig ◽  
Robert Garthoff ◽  
Sebastian Eppelt ◽  
...  
Keyword(s):  
Large Scale ◽  
Quantum Communication ◽  
Frequency Conversion ◽  
Single Atom ◽  
Quantum Network ◽  
Low Loss ◽  
Quantum Repeater ◽  
Long Distance ◽  
Quantum Networks ◽  
Network Links

Abstract Heralded entanglement between distant quantum memories is the key resource for quantum networks. Based on quantum repeater protocols, these networks will facilitate efficient large-scale quantum communication and distributed quantum computing. However, despite vast efforts, long-distance fibre based network links have not been realized yet. Here we present results demonstrating heralded entanglement between two independent, remote single-atom quantum memories generated over fibre links with a total length up to 33 km. To overcome the attenuation losses in the long optical fibres of photons initially emitted by the Rubidium quantum memories, we employ polarization-preserving quantum frequency conversion to the low loss telecom band. The presented work represents a milestone towards the realization of efficient quantum network links.

scholarly journals The Performance of Satellite-Based Links for Measurement-Device-Independent Quantum Key Distribution

Entropy ◽  
2021 ◽  
Vol 23 (8) ◽  
pp. 1010
Author(s):  
Guoqi Huang ◽  
Qin Dong ◽  
Wei Cui ◽  
Rongzhen Jiao
Keyword(s):  
Communication Network ◽  
Optical Fiber ◽  
Quantum Key Distribution ◽  
Large Scale ◽  
Quantum Communication ◽  
Weather Conditions ◽  
Key Distribution ◽  
Long Distance ◽  
Measurement Device ◽  
Measurement Device Independent

Measurement-device-independent quantum key distribution (MDI-QKD) protocol has high practical value. Satellite-based links are useful to build long-distance quantum communication network. The model of satellite-based links for MDI-QKD was proposed but it lacks practicality. This work further analyzes the performance of it. First, MDI-QKD and satellite-based links model are introduced. Then considering the operation of the satellite the performance of their combination is studied under different weather conditions. The results may provide important references for combination of optical-fiber-based links on the ground and satellite-based links in space, which is helpful for large-scale quantum communication network.

scholarly journals Comparing Calculated and Measured Losses in a Satellite-Earth Quantum Channel

2018 ◽  
pp. 14-19
Author(s):  
Máté Galambos ◽  
László Bacsárdi
Keyword(s):  
Quantum Channel ◽  
Large Scale ◽  
Quantum Communication ◽  
Weather Conditions ◽  
Experimental Results ◽  
Long Distance ◽  
Pointing Error ◽  
Optical Cable ◽  
Order Of Magnitude ◽  
Channel Loss

Long distance distribution of quantum states is necessary for quantum communication and large scale quantum experiments. Currently this distance is limited by channel loss. Previous theoretical analisys and proof of concept experiments showed that satellite quantum communication may have lower losses than optical cable based counterparts. Recently the QuESS experiment [3] realized the first satellite-Earth quantum channel. In this paper we compare heoretical predictions of different mathematical models with experimental results regarding channel loss. We examine the HV-5/7 model, HV-Night model and Greenwood model of optical turbulences, the geometric [4] and diffraction [5][6] models of beam wander and beam widening. Furthermore we take into account the effect of atmospheric gases and aerosols as well as the effect of pointing error. We find that theoretical predictions are largely in the same order of magnitude as experimental results. The exception is the diffraction model of beam spreading where our calculations yielded only one tenth of the measured value. Given the ever changing nature of weather conditions and the changing composition of atmospheric aerosoles we conclude that calculated and measured losses are in good agreement.

Going the Distance

2020 ◽  
Author(s):  
Ron Harris
Keyword(s):  
Large Scale ◽  
Western Europe ◽  
Family Firms ◽  
Global Trade ◽  
Long Distance ◽  
Business Corporation ◽  
Modern Economy ◽  
Key Factor ◽  
Silk Route ◽  
Passive Investors

Before the seventeenth century, trade across Eurasia was mostly conducted in short segments along the Silk Route and Indian Ocean. Business was organized in family firms, merchant networks, and state-owned enterprises, and dominated by Chinese, Indian, and Arabic traders. However, around 1600 the first two joint-stock corporations, the English and Dutch East India Companies, were established. This book tells the story of overland and maritime trade without Europeans, of European Cape Route trade without corporations, and of how new, large-scale, and impersonal organizations arose in Europe to control long-distance trade for more than three centuries. It shows that by 1700, the scene and methods for global trade had dramatically changed: Dutch and English merchants shepherded goods directly from China and India to northwestern Europe. To understand this transformation, the book compares the organizational forms used in four major regions: China, India, the Middle East, and Western Europe. The English and Dutch were the last to leap into Eurasian trade, and they innovated in order to compete. They raised capital from passive investors through impersonal stock markets and their joint-stock corporations deployed more capital, ships, and agents to deliver goods from their origins to consumers. The book explores the history behind a cornerstone of the modern economy, and how this organizational revolution contributed to the formation of global trade and the creation of the business corporation as a key factor in Europe's economic rise.

scholarly journals Future Power Train Solutions for Long-Haul Trucks

2021 ◽  
Vol 13 (4) ◽  
pp. 2225
Author(s):  
Ralf Peters ◽  
Janos Lucian Breuer ◽  
Maximilian Decker ◽  
Thomas Grube ◽  
Martin Robinius ◽  
...  
Keyword(s):  
Fuel Cells ◽  
Co2 Emissions ◽  
Value Chain ◽  
Large Scale ◽  
New Technology ◽  
Co2 Reduction ◽  
Road Transport ◽  
Transport Sector ◽  
Long Distance ◽  
Production Of Hydrogen

Achieving the CO2 reduction targets for 2050 requires extensive measures being undertaken in all sectors. In contrast to energy generation, the transport sector has not yet been able to achieve a substantive reduction in CO2 emissions. Measures for the ever more pressing reduction in CO2 emissions from transportation include the increased use of electric vehicles powered by batteries or fuel cells. The use of fuel cells requires the production of hydrogen and the establishment of a corresponding hydrogen production system and associated infrastructure. Synthetic fuels made using carbon dioxide and sustainably-produced hydrogen can be used in the existing infrastructure and will reach the extant vehicle fleet in the medium term. All three options require a major expansion of the generation capacities for renewable electricity. Moreover, various options for road freight transport with light duty vehicles (LDVs) and heavy duty vehicles (HDVs) are analyzed and compared. In addition to efficiency throughout the entire value chain, well-to-wheel efficiency and also other aspects play an important role in this comparison. These include: (a) the possibility of large-scale energy storage in the sense of so-called ‘sector coupling’, which is offered only by hydrogen and synthetic energy sources; (b) the use of the existing fueling station infrastructure and the applicability of the new technology on the existing fleet; (c) fulfilling the power and range requirements of the long-distance road transport.

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