Toward implementation of coding for quantum sources and channels

We review our experiment on quantum source and channel codings, the most fundamental operations in quantum info-communications. For both codings, entangling letter states is essential. Our model is based on the polarization-location coding, and a quasi-single photon linear optics implementation to entangle the polarization and location degrees of freedom. Using single-photon events in a subset of possible cases, we simulate quantum coding-decoding operations for nonorthogonal states under the quasi-pure state condition. In the quantum channel coding, we double the spatial bandwidth (number of optical paths), and demonstrate the information more than double can be transmitted. In the quantum source coding, we halve the spatial bandwidth to compress the data and decompress the original data with the high fidelity approaching the theoretical limit.

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POLARIZATION ENTANGLEMENT CONCENTRATIONS WITH LESS-HYPERENTANGLED PHOTON PAIRS IN MULTIPLE DEGREES OF FREEDOM

International Journal of Quantum Information ◽

10.1142/s021974991250075x ◽

2012 ◽

Vol 10 (07) ◽

pp. 1250075 ◽

Cited By ~ 2

Author(s):

YING GUO ◽

HONGYAN KUANG ◽

DAZU HUANG ◽

ZHISHENG ZHAO

Keyword(s):

Degrees Of Freedom ◽

Single Photon ◽

Degree Of Freedom ◽

Entanglement Concentration ◽

Channel Noise ◽

Entangled State ◽

Linear Optics ◽

Long Distance ◽

Multiple Degrees Of Freedom ◽

Photon Pairs

We demonstrate two entanglement concentration protocols (ECPs) for photon pairs in less-hyperentanglement, the simultaneous entanglement in multiple degrees of freedom. Using these ECPs, some maximally entangled states in polarization can be reconstructed deterministically from less-hyperentangled ones shared between remote participants. Both of the success probabilities are 100% in principle, and they do not require additional single photons. The former is implemented with the passive linear optics, which is achievable with current technology. The later adopts the cross-Kerr nonlinearity media to complete this task, which can increase the efficiency of the entanglement concentration process since it does not require the sophisticated single-photon detectors for measurements. The two ECPs are useful for practical long-distance quantum communication due to the fact that the entangled state in either the spatial degree of freedom or the frequency degree of freedom suffers little from channel noise in optical fiber.

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Scattering in Terms of Bohmian Conditional Wave Functions for Scenarios with Non-Commuting Energy and Momentum Operators

Entropy ◽

10.3390/e23040408 ◽

2021 ◽

Vol 23 (4) ◽

pp. 408

Author(s):

Matteo Villani ◽

Guillermo Albareda ◽

Carlos Destefani ◽

Xavier Cartoixà ◽

Xavier Oriols

Keyword(s):

Single Particle ◽

Degrees Of Freedom ◽

Single Photon ◽

Open Quantum Systems ◽

Wave Functions ◽

Practical Application ◽

Light Matter Interaction ◽

Pure States ◽

Energy And Momentum ◽

Full Quantum

Without access to the full quantum state, modeling quantum transport in mesoscopic systems requires dealing with a limited number of degrees of freedom. In this work, we analyze the possibility of modeling the perturbation induced by non-simulated degrees of freedom on the simulated ones as a transition between single-particle pure states. First, we show that Bohmian conditional wave functions (BCWFs) allow for a rigorous discussion of the dynamics of electrons inside open quantum systems in terms of single-particle time-dependent pure states, either under Markovian or non-Markovian conditions. Second, we discuss the practical application of the method for modeling light–matter interaction phenomena in a resonant tunneling device, where a single photon interacts with a single electron. Third, we emphasize the importance of interpreting such a scattering mechanism as a transition between initial and final single-particle BCWF with well-defined central energies (rather than with well-defined central momenta).

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Implementation of a single-photon fully quantum router with cavity QED and linear optics

Optical and Quantum Electronics ◽

10.1007/s11082-020-02701-1 ◽

2021 ◽

Vol 53 (1) ◽

Author(s):

Cong Cao ◽

Yu-Hong Han ◽

Xin Yi ◽

Pan-Pan Yin ◽

Xiu-Yu Zhang ◽

...

Keyword(s):

Cavity Qed ◽

Single Photon ◽

Linear Optics ◽

Quantum Router

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Research on Secure Debugging Interaction of Sensor Nodes Based on Visible Light Communication

Sensors ◽

10.3390/s21030953 ◽

2021 ◽

Vol 21 (3) ◽

pp. 953 ◽

Cited By ~ 1

Author(s):

Yuanchu Yin ◽

Jiefan Qiu ◽

Zhiqiang Li ◽

Mingsheng Cao

Keyword(s):

Visible Light ◽

Channel Coding ◽

Sensor Node ◽

Source Coding ◽

Visible Light Communication ◽

Propagation Characteristic ◽

Transmission Efficiency ◽

Sensor Nodes ◽

Pulse Interval ◽

Inaccessible Area

When a wireless sensor node’s wireless communication fails after being deployed in an inaccessible area, the lost node cannot be repaired through a debugging interaction that relies on that communication. Visible light communication (VLC) as a supplement of radio wave communication can improve the transmission security at the physical layer due to its unidirectional propagation characteristic. Therefore, we implemented a VLC-based hybrid communication debugging system (HCDS) based on VLC using smartphone and sensor node. For the system’s downlink, the smartphone is taken as the VLC gateway and sends the debugging codes to the sensor node by the flashlight. To improve the transmission efficiency of the downlink, we also propose a new coding method for source coding and channel coding, respectively. For the source coding, we analyze the binary instructions and compress the operands using bitmask techniques. The average compression rate of the binary structure reaches 84.11%. For the channel coding, we optimize dual-header pulse interval (DH-PIM) and propose overlapped DH-PIM (ODH-PIM) by introducing a flashlight half-on state. The flashlight half-on state can improve the representation capability of individual symbols. For the uplink of HCDS, we use the onboard LED of the sensor node to transmit feedback debugging information to the smartphone. At the same time, we design a novel encoding format of DH-PIM to optimize uplink transmission. Experimental results show that the optimized uplink transmission time and BER are reduced by 10.71% and 22%, compared with the original DH-PIM.

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Multiparticle quantum plasmonics

Nanophotonics ◽

10.1515/nanoph-2019-0517 ◽

2020 ◽

Vol 9 (6) ◽

pp. 1243-1269 ◽

Cited By ~ 2

Author(s):

Chenglong You ◽

Apurv Chaitanya Nellikka ◽

Israel De Leon ◽

Omar S. Magaña-Loaiza

Keyword(s):

Quantum Dynamics ◽

Degrees Of Freedom ◽

Single Photon ◽

Quantum Systems ◽

Many Body ◽

Statistical Fluctuations ◽

Quantum Plasmonics ◽

Control Of Quantum Systems ◽

Multiparticle Systems ◽

Quantum Photonics

AbstractA single photon can be coupled to collective charge oscillations at the interfaces between metals and dielectrics forming a single surface plasmon. The electromagnetic near-fields induced by single surface plasmons offer new degrees of freedom to perform an exquisite control of complex quantum dynamics. Remarkably, the control of quantum systems represents one of the most significant challenges in the field of quantum photonics. Recently, there has been an enormous interest in using plasmonic systems to control multiphoton dynamics in complex photonic circuits. In this review, we discuss recent advances that unveil novel routes to control multiparticle quantum systems composed of multiple photons and plasmons. We describe important properties that characterize optical multiparticle systems such as their statistical quantum fluctuations and correlations. In this regard, we discuss the role that photon-plasmon interactions play in the manipulation of these fundamental properties for multiparticle systems. We also review recent works that show novel platforms to manipulate many-body light-matter interactions. In this spirit, the foundations that will allow nonexperts to understand new perspectives in multiparticle quantum plasmonics are described. First, we discuss the quantum statistical fluctuations of the electromagnetic field as well as the fundamentals of plasmonics and its quantum properties. This discussion is followed by a brief treatment of the dynamics that characterize complex multiparticle interactions. We apply these ideas to describe quantum interactions in photonic-plasmonic multiparticle quantum systems. We summarize the state-of-the-art in quantum devices that rely on plasmonic interactions. The review is concluded with our perspective on the future applications and challenges in this burgeoning field.

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