Quantum information with highly-accessible continuous variable state of light: local oscillators and long-range quantum networks (Conference Presentation)

2017 ◽  
Author(s):  
Raphael C. Pooser
Keyword(s):  
Quantum Information ◽  
Long Range ◽  
Continuous Variable ◽  
Local Oscillators ◽  
Quantum Networks

scholarly journals Entangled resource for interfacing single- and dual-rail optical qubits

Quantum ◽  
2021 ◽  
Vol 5 ◽  
pp. 416
Author(s):  
David Drahi ◽  
Demid V. Sychev ◽  
Khurram K. Pirov ◽  
Ekaterina A. Sazhina ◽  
Valeriy A. Novikov ◽  
...  
Keyword(s):  
Quantum Information ◽  
Single Photon ◽  
Continuous Variable ◽  
Optical Field ◽  
The Other ◽  
Quantum Networks ◽  
Other Hand

Today's most widely used method of encoding quantum information in optical qubits is the dual-rail basis, often carried out through the polarisation of a single photon. On the other hand, many stationary carriers of quantum information – such as atoms – couple to light via the single-rail encoding in which the qubit is encoded in the number of photons. As such, interconversion between the two encodings is paramount in order to achieve cohesive quantum networks. In this paper, we demonstrate this by generating an entangled resource between the two encodings and using it to teleport a dual-rail qubit onto its single-rail counterpart. This work completes the set of tools necessary for the interconversion between the three primary encodings of the qubit in the optical field: single-rail, dual-rail and continuous-variable.

scholarly journals On-chip continuous-variable quantum entanglement

Nanophotonics ◽  
2016 ◽  
Vol 5 (3) ◽  
pp. 469-482 ◽  
Author(s):  
Genta Masada ◽  
Akira Furusawa
Keyword(s):  
Quantum Information ◽  
Integrated Circuits ◽  
Quantum Entanglement ◽  
Information Science ◽  
Essential Feature ◽  
Continuous Variable ◽  
Entangled State ◽  
Discrete Variable ◽  
Light Beams ◽  
Optical Circuits

AbstractEntanglement is an essential feature of quantum theory and the core of the majority of quantum information science and technologies. Quantum computing is one of the most important fruits of quantum entanglement and requires not only a bipartite entangled state but also more complicated multipartite entanglement. In previous experimental works to demonstrate various entanglement-based quantum information processing, light has been extensively used. Experiments utilizing such a complicated state need highly complex optical circuits to propagate optical beams and a high level of spatial interference between different light beams to generate quantum entanglement or to efficiently perform balanced homodyne measurement. Current experiments have been performed in conventional free-space optics with large numbers of optical components and a relatively large-sized optical setup. Therefore, they are limited in stability and scalability. Integrated photonics offer new tools and additional capabilities for manipulating light in quantum information technology. Owing to integrated waveguide circuits, it is possible to stabilize and miniaturize complex optical circuits and achieve high interference of light beams. The integrated circuits have been firstly developed for discrete-variable systems and then applied to continuous-variable systems. In this article, we review the currently developed scheme for generation and verification of continuous-variable quantum entanglement such as Einstein-Podolsky-Rosen beams using a photonic chip where waveguide circuits are integrated. This includes balanced homodyne measurement of a squeezed state of light. As a simple example, we also review an experiment for generating discrete-variable quantum entanglement using integrated waveguide circuits.

scholarly journals Diamond-based quantum technologies

Photoniques ◽  
2021 ◽  
pp. 44-48
Author(s):  
Toeno Van Der Sar ◽  
Tim Hugo Taminiau ◽  
Ronald Hanson
Keyword(s):  
Quantum Computation ◽  
Long Range ◽  
Quantum Coherence ◽  
Room Temperature ◽  
Science And Technology ◽  
Quantum Networks ◽  
Key Characteristics ◽  
Quantum Sensing ◽  
Quantum Science

Optically accessible spins associated with defects in diamond provide a versatile platform for quantum science and technology. These spins combine multiple key characteristics, including long quantum coherence times, operation up to room temperature, and the capability to create long-range entanglement links through photons. These unique properties have propelled spins in diamond to the forefront of quantum sensing, quantum computation and simulation, and quantum networks.

scholarly journals Entanglement 25 Years after Quantum Teleportation: Testing Joint Measurements in Quantum Networks

Entropy ◽  
2019 ◽  
Vol 21 (3) ◽  
pp. 325 ◽  
Author(s):  
Nicolas Gisin
Keyword(s):  
Quantum Information ◽  
Quantum State ◽  
Quantum Teleportation ◽  
Information Science ◽  
Science And Technology ◽  
Quantum Measurements ◽  
Quantum Information Science ◽  
Joint Measurement ◽  
Quantum Networks

Twenty-five years after the invention of quantum teleportation, the concept of entanglement gained enormous popularity. This is especially nice to those who remember that entanglement was not even taught at universities until the 1990s. Today, entanglement is often presented as a resource, the resource of quantum information science and technology. However, entanglement is exploited twice in quantum teleportation. Firstly, entanglement is the “quantum teleportation channel”, i.e., entanglement between distant systems. Second, entanglement appears in the eigenvectors of the joint measurement that Alice, the sender, has to perform jointly on the quantum state to be teleported and her half of the “quantum teleportation channel”, i.e., entanglement enabling entirely new kinds of quantum measurements. I emphasize how poorly this second kind of entanglement is understood. In particular, I use quantum networks in which each party connected to several nodes performs a joint measurement to illustrate that the quantumness of such joint measurements remains elusive, escaping today’s available tools to detect and quantify it.

scholarly journals Quantum Information Remote Carnot Engines and Voltage Transformers

Entropy ◽  
2019 ◽  
Vol 21 (2) ◽  
pp. 127 ◽  
Author(s):  
Jose Diazdelacruz ◽  
Miguel Martin-Delgado
Keyword(s):  
Quantum Information ◽  
Long Range ◽  
Physical System ◽  
Thermal Equilibrium ◽  
Heat Bath ◽  
Magnetic Interactions ◽  
Electrical Network ◽  
Heat Engines ◽  
Different Temperatures ◽  
Available Information

A physical system out of thermal equilibrium is a resource for obtaining useful work when a heat bath at some temperature is available. Information Heat Engines are the devices which generalize the Szilard cylinders and make use of the celebrated Maxwell demons to this end. In this paper, we consider a thermo-chemical reservoir of electrons which can be exchanged for entropy and work. Qubits are used as messengers between electron reservoirs to implement long-range voltage transformers with neither electrical nor magnetic interactions between the primary and secondary circuits. When they are at different temperatures, the transformers work according to Carnot cycles. A generalization is carried out to consider an electrical network where quantum techniques can furnish additional security.

scholarly journals Generating superposition of up-to three photons for continuous variable quantum information processing

2013 ◽  
Vol 21 (5) ◽  
pp. 5529 ◽  
Author(s):  
Mitsuyoshi Yukawa ◽  
Kazunori Miyata ◽  
Takahiro Mizuta ◽  
Hidehiro Yonezawa ◽  
Petr Marek ◽  
...  
Keyword(s):  
Information Processing ◽  
Quantum Information ◽  
Quantum Information Processing ◽  
Continuous Variable

Observation of strong continuous-variable Einstein-Podolsky-Rosen entanglement using shaped local oscillators

2016 ◽  
Author(s):  
Ami Shinjo ◽  
Naoyuki Hashiyama ◽  
Akane Koshio ◽  
Yujiro Eto ◽  
Takuya Hirano
Keyword(s):  
Continuous Variable ◽  
Local Oscillators ◽  
Einstein Podolsky Rosen
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