Quantum Hilbert Image Scrambling

Analogies between quantum image processing (QIP) and classical one indicate that quantum image scrambling (QIS), as important as quantum Fourier transform (QFT), quantum wavelet transform (QWT) and etc., should be proposed to promote QIP. Image scrambling technology is commonly used to transform a meaningful image into a disordered image by permutating the pixels into new positions. Although image scrambling on classical computers has been widely studied, we know much less about QIS. In this paper, the Hilbert image scrambling algorithm, which is commonly used in classical image processing, is carried out in quantum computer by giving the scrambling quantum circuits. First, a modified recursive generation algorithm of Hilbert scanning matrix is given. Then based on the flexible representation of quantum images, the Hilbert scrambling quantum circuits, which are recursive and progressively layered, is proposed. Theoretical analysis indicates that the network complexity scales squarely with the size of the circuit’s input n.     

Quantum Circuit Realization of Morphological Gradient for Quantum Grayscale Image

In this paper, based on the principle of classical morphology operations, the flat grayscale dilation and erosion operations are proposed for NEQR quantum image model. Furthermore, through combining these two morphology operations, we further realize the morphological gradient operation. As the basis of designing of grayscale morphology operations, a series of quantum circuit designs arepresented, which includes special add one operation UA₁(n) and special subtract one operation US₁(n) both for an n-length qubits sequence, quantum unitary operation U_C, parallel subtractor (PS) module, quantum comparator output the large QCOL and quantum comparator output the small QCOS modules. When designsthe concrete quantum circuit, a sequence of UA₁(n) and US₁(n) modules are used to obtain the quantum image sets based on the shape of specific structuring element. Then, the searching for maximaor minima in a certain space is involved, which can be solved by cascading a series of QCOL and QCOS modules in certain order. Finally, the PS module can be used to calculate the difference of the maxima and minima for producing the morphological gradient. The circuit’s complexity analysis illustrate that our scheme is very lower to the classical morphology operations.

     

Realization of Two-Qutrit Quantum Gates with Control Pulses

We investigate the realization of 2-qutrit logic gate in a bipartite 3-level system with qusi-Ising interaction. On the basis of Caftan decomposition of matrices, the unitary matrices of 2-qutrit are factorized into products of a series of realizable matrices. It is equivalent to exerting a certain control field on the system, and the control goal is usually gained by a sequence of control pulses. The general discussion on the realization of 2-qutrit logic gate is made first, and then the realization of the ternary SWAP gate and the ternary √SWAP gate are discussed specifically, and the sequences of control pulses and drift processes implementing these gates are given.     

Realization of Quantum Maxwell's Demon with Solid-State Spins

We report experimental realization of a quantum version of Maxwell's demon using solid state spins where the information acquiring and feedback operations by the demon are achieved through conditional quantum gates.A unique feature of this implementation is that the demon can start in a quantum superposition state or in an entangled state with an ancilla observer. Through quantum state tomography, we measure the entropy in the system, demon, and the ancilla, showing the influence of coherence and entanglement on the result. A quantum implementation of Maxwell's demon adds more controllability to this paradoxical thermal machine and may find applications in quantum thermodynamics involving microscopic systems.     

二维量子随机行走及其物理实现

近年来量子随机行走相关课题因其非经典的特性,已经成为越来越多科研人员的研究热点。这篇文章中我们回顾了一维经典随机行走和一维量子随机行走模型,并且在分析两种二维经典随机行走模型的基础上,我们构建二维量子随机行走模型。通过对随机行走者的位置分布标准差的计算,我们可以证明基于这种二维量子随机行走模型的算法优于其他上述随机行走。除此之外,我们提出一个利用线性光学方法的实验方案,实现这种二维量子随机行走模型。     

Quantum Multi-Image Encryption Based on Iteration Arnold Transform with Parameters and Image Correlation Decomposition

A novel quantum multi-image encryption algorithm based on iteration Arnold transform with parameters and image correlation decomposition is proposed, and a quantum realization of the iteration Arnold transform with parameters is designed. The corresponding low frequency images are obtained by performing 2-D discrete wavelet transform on each image respectively, and then the corresponding low frequency images are spliced randomly to one image. The new image is scrambled by the iteration Arnold transform with parameters, and the gray-level information of the scrambled image is encoded by quantum image correlation decomposition. For the encryption algorithm, the keys are iterative times, added parameters, classical binary and orthonormal basis states. The key space, the security and the computational complexity are analyzed, and all of the analyses show that the proposed encryption algorithm could encrypt multiple images simultaneously with lower computational complexity compared with its classical counterparts.     

On Super-RS Algebra and Drinfeld Realization of Quantum Affine Superalgebras

We describe the realization of the super-Reshetikhin–Semenov-Tian-Shansky (RS) algebra in quantum affine superalgebras, thus generalizing the approach of Frenkel and Reshetikhin to the supersymmetric (and twisted) case. The algebraic homomorphism between the super-RS algebra and the Drinfeld current realization of quantum affine superalgebras is established by using the Gauss decomposition technique of Ding and Frenkel. As an application, we obtain Drinfeld realization of quantum affine superalgebra U_q [osp(1|2)⁽¹⁾] and its degeneration – central extended super-Yangian double DY [osp(12)⁽¹⁾].     

Linear Optical Realization of Qubit Purification with Quantum Amplitude Damping Channel

We provide an experimental scheme which includes the realizatlon of quantum amplitude damping channel and the optimal two-qubit purification. Moreover, we discuss the purification of arbitrary input qubits and arbitrary N qubits. Our scheme only uses linear optical elements and the proposal may be useful in transmission of photons in fibres. This scheme is feasible in the laboratory with the current experimental technology.     

Supplemental Materials: Realization of Quantum Maxwell's Demon with Solid-State Spins

正A:Experimental Setup We use a home-built confocal microscopy with an oil immersed objective lens to address and detect single nitrogen vacancy(NV)centers in a single-crystal diamond sample,which is mounted on a doughnut shape,three-axis,closed-loop piezoelectric actuator     

New Operator Realization of Superoperators and Its Application in Quantum Information Theory

By exposing deficiency of the usual superoperators that have no explicit operator-expression in quantum information theory we introduce thermo entangled state representation to endow each of these superoperators a definite operator-expression in an enlarged space in which one mode is a fictitious. This helps us to directly derive the role of exponential of superoperators and the solutions of some master equations.     

The Elliptic Algebra and the Drinfeld Realization of the Elliptic Quantum Group

By using the elliptic analogue of the Drinfeld currents in the elliptic algebra , we construct a L-operator, which satisfies the RLL-relations characterizing the face type elliptic quantum group . For this purpose, we introduce a set of new currents in . As in the N=2 case, we find a structure of as a certain tensor product of and a Heisenberg algebra. In the level-one representation, we give a free field realization of the currents in . Using the coalgebra structure of and the above tensor structure, we derive a free field realization of the -analogue of -intertwining operators. The resultant operators coincide with those of the vertex operators in the -type face model.     

Quantum Spinor Structures for Quantum Spaces

A general theory of quantum spinor structures on quantum spaces is presented within the formalism of quantum principal bundles. Quantum analogs of basic objects of the classical theory are constructed: Laplace and Dirac operators, quantum versions of Clifford and spinor bundles, a Hodge *-operator, integration operators. Quantum phenomena are discussed, including an example of the Dirac operator associated to a quantum Hopf fibration.     

Brüschweiler量子搜索算法的改进及其实验实现

量子计算与经典计算相比, 能够极大地提高运算速度, 解决一些经典计算不能解决或很难解决的问题. 对于在无序数据库中进行搜索这类问题, 可以用量子算法, 如Brüschweiler量子搜索算法来解决. 与经典算法相比, Brüschweiler量子算法能够指数次地提高搜索速度. 在Brüschweiler提出的算法中, 数据量子位和观测量子位(辅助量子位)是分开的, 属于不同的量子位. 通过研究, 对Brüschweiler算法作了改进, 使之不需要用辅助量子位, 就可以达到指数次提高搜索速度的目的. 改进后的Brüschweiler量子算法有利于简化实验的设计和实现过程. 同时还利用核磁共振实验, 演示了改进后的Brüschweiler量子算法的实现.     

Experimental Realization of Arbitrary Accuracy Iterative Phase Estimation Algorithms on Ensemble Quantum Computers

We report the first experimental demonstration of a nuclear phase estimation algorithms. Using feedback and iterations, magnetic resonance （NMR） realization of iterative we experimentally obtain the phase with 6 bits of precision on a two-qubit NMR quantum computer. Furthermore, we experimentally demonstrate the effect of gate noise on the iterative phase estimation algorithm. Our experimental results show that errors of measurements of the phase depend strongly on the precision of coupling gates. This experiment can be used as a benchmark for multi-qubit realizations of quantum information processing and precision measurements.     

离子阱中共线两离子基本量子逻辑门的实现

运用量子理论,在Paul阱中共线两离子系统的精确解的基础上,结合量子编码方法,讨论了囚禁两离子系统量子非门(单比特逻辑非门、两比特逻辑非门)实现的理论方法,提出利用质心振动模和两离子构建量子与门的理论方法(不需第三个离子),通过分析,证明了囚禁两离子系统在相对量子数l=1时,可制备为单比特量子非门和量子与门的线性叠加,可以完成并行量子逻辑操作,量子非门和量子与门是构成量子计算机制基本结构单元,值得我们在量子信息实验研究中加以考虑.     

Construction of Arnold tongue structures for coupled periodic oscillators

Arnold tongue structures generated due to the mutual entrainment of two periodic oscillators are studied experimentally and numerically. This mutual entrainment is provoked due to the mutual (bidirectional) coupling between the two oscillators. In experiments, this bidirectional coupling is achieved by immersing a pair of anodes (oscillators) in a common electrolytic solution. A voltage mismatch between these anodes renders the time period of the uncoupled oscillators non-identical. Moreover, the coupling strength between the two oscillators is uniquely determined by the Euclidean distance separating them. Systematically varying the distance between these two anodes as a function of their voltage mismatch, phase locked domains were located. Subsequently, Arnold tongue structures were constructed in the experiments. Numerical simulations, using a model for electrochemical corrosion, corroborate our experimental findings.     

On the Existence of Quantum Signature for Quantum Messages

Quantum signature (QS) is used to authenticate the identity of the originator, ensure data integrity and provide non-repudiation service with unconditional security. Depending on whether a trusted third party named arbitrator is involved or not, QS is classified as arbitrated QS and true QS. This paper studies existence problem about the two kinds of QS and contributes to two points: (1) a basic framework is provided to analyze the possibility of arbitrated QS on signing quantum messages; (2) disagreement between the impossibility of true QS and an existing true QS scheme is solved.     

A Hilbert Space Realization of Nonlinear Quantum Mechanics as Classical Extension of Its Linear Counterpart

This paper studies the state-effect-probability structure associated with thequantum mechanics of nonlinear (homogeneous, in general nonadditive) operatorson a Hilbert space. Its aim is twofold: to provide a concrete representation ofthe features of nonlinear quantum mechanics on a Hilbert space, and to showthat the properties of the nonlinear version of quantum mechanics here describedhave the structure of a classical logic.     

Possible Realization of Cluster States and Quantum Information Transfer in Cavity QED via Raman Transition

We present a scheme to generate cluster states with many scheme, no transfer of quantum information between the atoms in cavity QED via Raman transition. In this atoms and cavities is required, the cavity fields are only virtually excited and thus the cavity decay is suppressed during the generation of cluster states. The atoms are always populated in the two ground states. Therefore, the scheme is insensitive to the atomic spontaneous emission and cavity decay. We also show how to transfer quantum information from one atom to another.