(A2)-PROJECT-2

Nobel Prize to Aspect-Clauser-Zeilinger

Experiments with Entangled Photons & Pioneering Quantum Information Science Experiments:

Click: Nobel-Prize-2022/

Nobel Prize to Hopfield-Hinton

For Using Principles of Physics to Develop Artificial Intelligence (AI) Systems Such as Neural Networks

Click: PHYSICS-NOBEL-PRIZE-2024

Like Neural Networks, Quantum Network is also an Artificial Intelligence (AI) System.

Development of Quantum Network using Entanglement is an Artificial Intellengence (AI) Project.

PROJECT-2

(P. S. Bhatia)

Quantum Information Science (QIS),

Quantum Artificial Intelligence (QAI),

Quantum Engineering,

Quantum Communication,

Quantum Entanglement,

Quantum Internet

Use this Page to Download Pdf Files:

PROJECT-2

(To Download Scroll-Down This Page)

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Entanglement: Spooky Action at a Distance.

----- Albert Einstein

It seems that laws of physics present no barrier to reducing the size of computer until the bits are reduced to the size of atoms and the quantum behavior holds the dominant sway.

----- Richard P. Feynman

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Click For : Quantum Entanglement

Click For: Multipartite Entanglement

Generating Entangled State of Increasing Complexity is Key to Next generation of

Quantum Information Technology (QIT)

Above Figure Shows Multi-Particle (Multi-Qubit) Entangled States

Entanglement in multi-qubit states is more complicated than in two-qubit entanglement. Such multi-qubit entangled states have bizarre new quantum properties. Theoretically, the subject of multi-qubit entanglement is very poorly understood and experimentally very little work has been done on multi-qubit entanglement. Further, multi-qubit entanglement give rise to striking contradiction with local realism for non statistical prediction of quantum mechanics.

Such multi-qubit states are used to establish quantum connection for quantum communication, among quantum microprocessors, both within the quantum computers and among nodes of quantum internet. Therefore, such quantum entangled states provides entanglement resource for Quantum Interconnections (QuICs) (D. Awschalom et al., PRX Quantum 2, 017002 (2021); J. Wang et al., Optica 3 (4), 407 (2016)) required for building next generation of quantum information technology (QIT) such as Modular Quantum Computers and Global Scale Quantum Internet.

Such multi-qubit states are also used for one-way quantum computing, topological quantum computing, testing foundation of quantum mechanics, and for improving detection sensitivity of atomic & molecular spectroscopy (D. J. Wineland et al., Science 304, 1476 (2004)).

Research Overview

Quantum Superposition and Quantum Entanglement (Greenberger, Horne, & Zeilinger, Phys. Today 46 (8), 22 (Aug. 1993); R. Horodecki et al., Rev. Mod. Phys. 81, 865 (2009)) are bed rocks on which current paradigm of quantum information is resting. Superposition and entanglement are playing pivotal role for building next generation of quantum information technology (QIT) such as quantum computer and quantum internet. Quantum computer is a next generation of computing machine, which is exponentially faster than present day existing classical digital computers. Quantum internet is a next generation of computer internet, which has exponentially larger state-space that allow much more efficient & secure information transfer then existing classical computer internet. In this Quantum Communication project, which is based on Quantum Entanglement, we generate Complex Multi-Photon Quantum Entangled States (M. Hein, J. Eisert, & H. J. Briegel, Phys. Rev. A 69, 062311 (2004); I. D. K. Brown et al., J. Phys. A 38 (5), 1119-1131 (2005); A. Borras et al., J. Phys. A 40 (44), 13407-13421 (2007)) in the laboratory and then using these laboratory generated states conduct prototype multi-party photonic communication experiments (N. Paul et al., Quantum Inf. Process. 10 (5), 619-632 (2011)), which are useful for understanding communication of quantum information both within the quantum computer and among the nodes of quantum internet. In these experiments, high intensity Complex Multi-Photon Quantum Entangled States are generated by nonlinear optical technique of Chirped-Pulse Spontaneous Parametric Down-Conversion (SPDC) of ultrafast (/ femtosecond) optical pulses in solid-state nonlinear optical crystals. These Complex Multi-Photon Quantum Entangled States , which provide entanglement resource for communication, are then used as wireless quantum channels over which quantum information is transfer. In this project, these multi-party quantum communication experiments are finally upgraded to demonstrate a prototype wireless quantum communication photonic network.

Two-party (Alice & Bob) teleportation theory was originally given by Charles Bennett (Phys. Rev. Lett. 70 (13), 1895 (1993)). Entanglement resource used in this theory was two-particle EPR Bell states. This theory has been well verified in many experiments but for practical development of quantum internet two-party teleportation is not sufficient but require multi-party teleportation. My current publications present original research on multi-party teleportation. My current publications shows that two-particle EPR Bell states CANNOT be used to provide entanglement resource for multi-party quantum teleportation but entanglement resource for multi-party teleportation can be provided by multi-particle entangled states. My recent published research (P. S. Bhatia, Laser Physics 31 (9), 095203 (2021)) also shows that teleportation of qubit among nodes of a multi-node quantum network do not directly follow usual two-party teleportation theory of Bennett but in a multi-node quantum network qubit to be teleported is first split into fragments and then at the destination node of the quantum network, qubit is re-constructed from the fragments. My recent published research further shows that for development of an ideal quantum network, teleportation alone is not sufficient, but development of such quantum network imposes additional requirements. One such requirement is inseparability property of quantum channel that is used to quantum wire different nodes of a multi-node (with more than two nodes) quantum network. This research is important for development of next generation of Quantum Internet (M. Sasaki et al., IEEE J. Selected Topics in QE-21 (3), 6400313 (2015)). Development of Quantum Internet, under US Quantum Initiative Act, has been declared as a high priority research area by National Science Foundation (NSF) and US Department of Energy (DOE). Currently, there is a nation-wide effort to develop next generation of Quantum Internet. Therefore, research presented in this project is significant contribution to very rapidly advancing field of quantum communication. Majority of other researchers, at different Universities, are using two-qubit entangled states that can lead to communication only between two nodes of a quantum network. This is the only project in whole United State, which employ multi-qubit entangled states that leads to communication among nodes of a multi-node quantum network. Therefore, this project represents US leadership in the field of quantum communication.

Other possible projects are following: (a) Development of High-Intensity Multi-Photon Entangled Sources. (b) Quantum Frequency Conversion (QFC). (c) Inter-Conversion of atomic and photonic qubits. (d) Experimental demonstration of all Photonic Quantum Repeater.

Development of High-Intensity Multi-Photon Entangled Sources (Separate Experiment): Ultrafast Spontaneous Parametric Down-Conversion (SPDC) in nonlinear optical crystals is today the best source for generating EPR (Einstein-Podolsky-Rosen) correlated entangled photon pairs in the laboratory (Y. Shih, Rep. Prog. Phys. 66, (6), 1009 (2003)). Such EPR correlated entangled photons are building block for generating any multi-photon entangled state. Intensity of any multi-photon entangled state (such as GHZ or Cluster state) generated to date is not sufficient to permit their use in any multi-party quantum communication experiment. This is one of the principle stumbling block for developing next generation of quantum communication systems such as quantum internet. Photon flux of any multi-photon entangled state can be increased with techniques of Electromagnetically Induced Transparency (EIT) and Optical Parametric Chirped-Pulse Amplification (OPCPA). Where, OPCPA (R. Paschotta, Encyclopedia of Laser Physics and Technology, WILEY-VCH (2008)) is a technique very similar to Chirped Pulse Amplification (CPA), which is widely used to generate high-intensity ultra-short optical pulses in the laboratory (CLICK- (NOBEL-PRIZE-2018) (G. Mourou et al., IEEE J. QE-24 (2) pp. 398 (1988)). For generation of high-intensity quantum correlated entangled ultra-short optical pulses we use an Entangled Optical Parametric Oscillator (EOPO). In this oscillator a nonlinear photonic crystal (D. Bouwmeester et al., Phys. Rev. Lett. 93, 040504 (2004)) with electromagnetically induced transparency (EIT) is enclosed in a resonator formed by two end mirrors. Magnitude of second-order nonlinear susceptibility of photonic crystal, which is responsible for generating entangled photons, is much greater than that of Beta-Barium Borate (BBO), periodically poled Lithium Nobate (PPLN), & periodically poled Potassium Titanyl Phosphate (PPKTP) crystals, commonly used for entangled photons generation in the laboratory. EIT is used to further enhance magnitude of second order nonlinear susceptibility of the photonic crystal (J. D. Joannopoulos et al., Nature Material 3, 211 (2004)). Ultra-short optical pulses near 800 nm wavelength before entering into the input resonator mirror are expanded by a stretcher. Then down-converted signal and idler optical pulses near 1.5 micro meter wavelength after emerging out of output mirror of optical parametric oscillator, are compressed by a compressor. Orthogonally polarized signal and idler ultra-short entangled pulses at the telecommunication wavelength are separated with a polarizing beam splitter (PBS). This generate high-intensity quantum correlated EPR entangled ultra-short pulses of light. Then by using appropriate experimental technique, multiple copies of EPR entangled pulses are further entangled to generate any desired high-intensity multi-photon entangled state in the laboratory. Such high-intensity sources of multi-photon entangled states are crucial for development of photonic quantum repeaters and quantum internet.

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Above figure shows a Quantum Network. Green Circles represent Nodes. Dotted lines represent Quantum Interconnections created by Entanglement. Quantum Network is the Most Complex Artificial Intelligence System.

Click For: Quantum Network

Above figure shows architecture of a three node Atom-Photon Quantum Network. In this figure QM X, QM Y and QM Z are three atomic quantum memories, which are used to store a qubit. These memories represent three nodes of the quantum network. In this network qubit can be teleported from any node to any other node. Quantum memories operate at wavelength 895 nm and quantum network operate at telecom wavelength 1584 nm. QFC-1 and QFC-2: Quantum Frequency Converters. BSM is Bell-State Analyzer. PMF: Polarization Maintaining Fiber.

(Large-Scale Experiment)

For more details, download following Pdf files.

Download: BH-PUB-(A-NET) Pdf

Download: BH-PUB-(P-NET) Pdf

PHOTON NUMBER RESOLVING DETECTOR

Above Figure Shows Output of a Photon Number Resolving (PNR) Detector

Such Photon Number Resolving (PNR) detectors can count number of photons in optical pulse incident into the detector. These detectors are used with strongly attenuated femtosecond optical pulses required in some quantum information experiments. Such detectors are also used for some advanced quantum information applications such as generation of Complex Multi-Photon Entangled States, development of photonic Quantum Repeaters, and development of photonic Quantum internet.

Quantum Communication

Above Figure Shows Different Sub-Areas within Field of Quantum Communication.

Brief Description of this Project:

Brief Description of this project can be found in a pdf file with

name: PROJECT-2, which can be downloaded. To download this file click below.

Download: (*PROJECT-2) pdf

(Strongly Suggested to Download)

Publications & Presentation Related to this Project:

For seminar presentation on this project (PROJECT-2) click on Page: D-PRESENTATION, which is located on the TOP ROW of this Home Page. This presentation will allow you to view Complete Seminar Talk on this project, right on your computer screen. For Publications related to this project (PROJECT-2) click on Page: C-PUBLICATION, which is located on the TOP ROW of this Page.

National News Related to this Project

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Today's Physics Discovery is Tomorrow's Technology

(From Quantum Physics to Quantum Technology)

National Science Foundation (NSF) Announces Quantum Leap

Click For: NSF-QUANTUM-LEAP

National Science Foundation (NSF) Announces

Quantum Interconnect Challenges

Click: NSF-QuICs

September 4, 2024

Department of Energy (DOE) Announces $ 118 Millions for Research Centers in Quantum Information Science (QIS) and Related Research Areas.

Click: (2024)-DOE-NEWS

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Past Nobel Prizes Associated with this Project:

Experiments with Entangled Photons &

Pioneering Quantum Information Science

Click: Nobel-Prize-2022/

Manipulation of Individual Quantum systems

S. Haroche and D. J. Wineland

CLICK- (NOBEL-PRIZE-2012)

General Readings Related to this Project:

(1) Multiparticle Interferometry and Superposition Principle,

D. M. Greenberger, M. A. Horne, and A. Zeilinger, Phys. Today 46 (8), 22 (1993).

DOWNLOAD: (*READ-1) pdf

(2) Quantum information and Computation,

C. H. Bennett, Phys. Today 48 (10), 24 (1995).

DOWNLOAD: (*READ-2) pdf

(3) Quantum Teleportation,

A. Zeilinger, Scientific American pp. 50, April (2000).

DOWNLOAD: (*READ-3) pdf

(4) Quantum Computing with Ions,

D. J. Wineland et al., Scientific American, pp. 64 August (2008).

DOWNLOAD: (*READ-4) pdf

(5) Quantum Internet, H. J. Kimble, Nature 453, 1023 (2008).

DOWNLOAD: (*READ-5) pdf

(6) Multiphoton Entanglement and Interferometry,

A. Zeilinger et al., Rev. Mod. Phys. 84, 777 (2012).

DOWNLOAD: (*READ-6) pdf

Textbooks Related to this Project

Quantum Computing

Quantum Computing: A Short Course from Theory to Experiment

Joachim Stolze and Dieter Suter

Wiley-VCH-(2008)

Quantum Communication

Quantum Teleportation and Entanglement

A. Furusawa and P. van Loock

Wiley-VCH-(2011).

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