The Experts below are selected from a list of 26592 Experts worldwide ranked by ideXlab platform
Jonathan P Dowling - One of the best experts on this subject based on the ideXlab platform.
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vortex phase qubit generating arbitrary counterrotating coherent Superpositions in bose einstein condensates via optical angular momentum beams
Physical Review Letters, 2005Co-Authors: Kishore T Kapale, Jonathan P DowlingAbstract:We propose a scheme for the generation of arbitrary coherent Superpositions of vortex States in Bose-Einstein condensates (BEC) using the orbital-angular-momentum States of light. We devise a scheme to generate coherent Superpositions of two such counterrotating States of light using well-known experimental techniques. We show that a specially designed Raman scheme allows for transfer of the optical vortex-Superposition State onto an initially nonrotating BEC. This creates an arbitrary and coherent Superposition of a vortex and antivortex pair in the BEC. The ideas presented here could be extended to generate entangled vortex States, design memories for the orbital-angular-momentum States of light, and perform other quantum information tasks. Applications to inertial sensing are also discussed.
Quntao Zhuang - One of the best experts on this subject based on the ideXlab platform.
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quantum thermalization and equilibrium State with multiple temperatures
Laser Physics Letters, 2014Co-Authors: Quntao ZhuangAbstract:A large class of isolated quantum systems in a pure State can equilibrate and serve as a heat bath. We show that, once equilibrium is reached, any of its subsystems, which are much smaller than the isolated system, can be thermalized such that the subsystem is governed by the Gibbs distribution. Within this theoretical framework, the celebrated Superposition principle of quantum mechanics leads to a prediction of a thermalized subsystem with multiple temperatures when the isolated system is in a Superposition State of energy eigenStates of multiple distinct energy scales. This multiple-temperature State is at equilibrium, completely different from a non-equilibrium State that has multiple temperatures at different parts. Feasible experimental schemes, in particular with ultra-cold atoms, to verify this prediction are discussed.
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quantum thermalization and equilibrium State with multiple temperatures
arXiv: Statistical Mechanics, 2012Co-Authors: Quntao ZhuangAbstract:A large class of isolated quantum system in a pure State can equilibrate and serve as a heat bath. We show that once the equilibrium is reached, any of its subsystems that is much smaller than the isolated system is thermalized such that the subsystem is governed by the Gibbs distribution. Within this theoretical framework, the celebrated Superposition principle of quantum mechanics leads to a prediction of a thermalized subsystem with multiple temperatures when the isolated system is in a Superposition State of energy eigenStates of multiple distinct energy scales. This multiple-temperature State is at equilibrium, completely different from a non-equilibrium State that has multiple temperatures at different parts. Feasible experimental schemes to verify this prediction are discussed.
Lan Song - One of the best experts on this subject based on the ideXlab platform.
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multidimensional color image storage retrieval and compression based on quantum amplitudes and phases
Information Sciences, 2014Co-Authors: Rigui Zhou, Haisheng Li, Mingcui Li, Lan SongAbstract:Abstract In this study, we propose a new representation method for multidimensional color images, called an n -qubit normal arbitrary Superposition State (NASS), where n qubits represent the colors and coordinates of 2 n pixels (e.g., a three-dimensional color image of 1024 × 1024 × 1024 using only 30 qubits). Based on NASS, we present an ( n + 1 )-qubit normal arbitrary Superposition State with relative phases (NASSRP) and an ( n + 2 )-qubit normal arbitrary Superposition State with three components (NASSTC) for lossless and lossy quantum compression, respectively. We also design three general quantum circuits to generate NASS, NASSRP, and NASSTC States, where we retrieve an image from a quantum system using different projection measurement operators. Finally, we define the quantum compression ratio and analyze lossless and lossy quantum compression algorithms of multidimensional quantum images. For the first time, we implemented the compression of multidimensional color images on a quantum computer. Thus, we address the theoretical and practical aspects of image processing on a quantum computer.
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multi dimensional color image storage and retrieval for a normal arbitrary quantum Superposition State
Quantum Information Processing, 2014Co-Authors: Qingxin Zhu, Rigui Zhou, Lan Song, Xingjiang YangAbstract:Multi-dimensional color image processing has two difficulties: One is that a large number of bits are needed to store multi-dimensional color images, such as, a three-dimensional color image of $$1024 \times 1024 \times 1024$$1024?1024?1024 needs $$1024 \times 1024 \times 1024 \times 24$$1024?1024?1024?24?bits. The other one is that the efficiency or accuracy of image segmentation is not high enough for some images to be used in content-based image search. In order to solve the above problems, this paper proposes a new representation for multi-dimensional color image, called a $$(n\,+\,1)$$(n+1)-qubit normal arbitrary quantum Superposition State (NAQSS), where $$n$$n qubits represent colors and coordinates of $${2^n}$$2n pixels (e.g., represent a three-dimensional color image of $$1024 \times 1024 \times 1024$$1024?1024?1024 only using 30?qubits), and the remaining 1?qubit represents an image segmentation information to improve the accuracy of image segmentation. And then we design a general quantum circuit to create the NAQSS State in order to store a multi-dimensional color image in a quantum system and propose a quantum circuit simplification algorithm to reduce the number of the quantum gates of the general quantum circuit. Finally, different strategies to retrieve a whole image or the target sub-image of an image from a quantum system are studied, including Monte Carlo sampling and improved Grover's algorithm which can search out a coordinate of a target sub-image only running in $$O(\sqrt{N/r} )$$O(N/r) where $$N$$N and $$r$$r are the numbers of pixels of an image and a target sub-image, respectively.
Jinhyoung Lee - One of the best experts on this subject based on the ideXlab platform.
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quantum information processing for a coherent Superposition State via a mixedentangled coherent channel
Physical Review A, 2001Co-Authors: Hyunseok Jeong, M S Kim, Jinhyoung LeeAbstract:An entangled two-mode coherent State is studied within the framework of 2\ifmmode\times\else\texttimes\fi{}2-dimensional Hilbert space. An entanglement concentration scheme based on joint Bell-State measurements is worked out. When the entangled coherent State is embedded in vacuum environment, its entanglement is degraded but not totally lost. It is found that the larger the initial coherent amplitude, the faster entanglement decreases. We investigate a scheme to teleport a coherent Superposition State while considering a mixed quantum channel. We find that the decohered entangled coherent State may be useless for quantum teleportation as it gives the optimal fidelity of teleportation less than the classical limit 2/3.
Dan Stamperkurn - One of the best experts on this subject based on the ideXlab platform.
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generating macroscopic quantum Superposition States in momentum and internal State space from bose einstein condensates with repulsive interactions
Physical Review A, 2004Co-Authors: James Higbie, Dan StamperkurnAbstract:Resonant Raman coupling between internal levels can create double-well momentum-space potentials for multilevel ``periodically-dressed'' atoms. We develop a many-body formalism for a weakly interacting, trapped periodically dressed Bose gas which illustrates how a tunable exchange interaction yields correlated many-body ground States. In contrast to the case of a position-space double well, the ground State of stable periodically-dressed Bose gases with repulsive interactions tends toward a macroscopic Superposition State in the regime where interactions dominate the momentum-space tunneling induced by the external trapping potential. We discuss how real-time control of experimental parameters can be used to create macroscopic quantum Superpositions of either momentum or internal States, and how these States could be dynamically controlled, opening the way toward highly sensitive interferometry and frequency metrology.