Lattice-based Post-quantum Cryptography (PQC) can effectively resist the quantum threat to blockchain's underlying cryptographic algorithms. Blockchain node decryption is one of the most commonly used cryptographi...
详细信息
Ghost imaging sparsity constraints (GISC) spectral camera can acquire both spatial and spectral information of surface features, and has significant application prospects in the field of satellite remote sensing. This...
详细信息
A quantum autoencoder is a quantum neural network model for compressing information stored in quantum states. However, one needs to process information stored in quantum circuits for many tasks in the emerging quantum...
详细信息
A quantum autoencoder is a quantum neural network model for compressing information stored in quantum states. However, one needs to process information stored in quantum circuits for many tasks in the emerging quantuminformation technology. In this work, generalizing the ideas of classical and quantum autoencoders, we introduce the quantum circuit autoencoder (QCAE) model to compress and encode information within quantum circuits. We provide a comprehensive protocol for QCAE and design a variational quantum algorithm, varQCAE, for its implementation. We theoretically analyze this model by deriving conditions for lossless compression and establishing both upper and lower bounds on its recovery fidelity. Finally, we apply varQCAE to three practical tasks, and numerical results show that it can effectively (1) compress the information within quantum circuits, (2) detect anomalies in quantum circuits, and (3) mitigate the depolarizing noise in quantum circuits. These suggest that our algorithm is potentially applicable to other informationprocessing tasks for quantum circuits.
We introduce a general framework called neural-network- (NN) encoded variational quantumalgorithms (VQAs), or NNVQA for short, to address the challenges of implementing VQAs on noisy intermediate-scale quantum (NISQ)...
详细信息
We introduce a general framework called neural-network- (NN) encoded variational quantumalgorithms (VQAs), or NNVQA for short, to address the challenges of implementing VQAs on noisy intermediate-scale quantum (NISQ) computers. Specifically, NNVQA feeds input (such as parameters of a Hamiltonian) from a given problem to a neural network and uses its outputs to parameterize an ansatz circuit for the standard VQA. Combining the strengths of NN and parameterized quantum circuits, NNVQA can accelerate the training process of VQAs and handle a broad family of related problems with varying input parameters with the pretrained NN. To concretely illustrate the merits of NNVQA, we present results on a NN variational quantum eigensolver (VQE) for solving the ground state of parameterized XXZ spin models in one and two dimensions. Our results demonstrate that NNVQE is able to estimate the ground-state energies of parameterized Hamiltonians with high precision without fine tuning, and significantly reduce the overall training cost to estimate ground-state properties across the phases of the given Hamiltonian. We also employ an active learning strategy to further increase the training efficiency while maintaining prediction accuracy. These encouraging results demonstrate that NNVQAs offer an alternative hybrid quantum-classical paradigm to utilize NISQ resources for solving more realistic and challenging computational problems.
Optical computing harnesses the speed of light to perform vector-matrix operations efficiently. It leverages interference, a cornerstone of quantum computing algorithms, to enable parallel computations. In this work, ...
详细信息
Optical computing harnesses the speed of light to perform vector-matrix operations efficiently. It leverages interference, a cornerstone of quantum computing algorithms, to enable parallel computations. In this work, we interweave quantum computing with classical structured light by formulating the process of photonic matrix multiplication using quantum mechanical principles such as state superposition and subsequently demonstrate a well-known algorithm, namely, Deutsch-Jozsa's algorithm. This is accomplished by elucidating the inherent tensor product structure within the Cartesian transverse degrees of freedom of light, which is the main resource for optical vector-matrix multiplication. To this end, we establish a discrete basis using localized Gaussian modes arranged in a lattice formation and demonstrate the operation of a Hadamard gate. Leveraging the reprogrammable and digital capabilities of spatial light modulators, coupled with Fourier transforms by lenses, our approach proves adaptable to various algorithms. Therefore, our work advances the use of structured light for quantuminformationprocessing. (c) 2024 Author(s).
Composite pulse segmentation has emerged as a promising error-mitigation technique for a wide range of physical systems. In recent years, composite schemes were applied as mitigation strategies for quantuminformation...
详细信息
Composite pulse segmentation has emerged as a promising error-mitigation technique for a wide range of physical systems. In recent years, composite schemes were applied as mitigation strategies for quantuminformationprocessing and quantum computing. However, most of these strategies assume full error correlation between segments, which can result in gates with worse fidelity performance compared to noncomposite gates. In our research, we investigate how error correlations impact the fidelity of quantum gates within the composite segmentation framework. In our study, we prove the existence of a critical correlation threshold, above which the composite pulse method significantly enhances both the mean value and variance of the fidelity. To gain deeper insights, we analyze various properties of the threshold in the realm of integrated photonics, including the effects of geometrical variations and the limit where the number of segments approaches infinity. We numerically explore diverse scenarios, showcasing different aspects of the critical threshold within the photonic quantum gates framework. These findings contribute to new pathways of error-mitigation strategies and their implications in quantuminformationprocessing.
the use of No-SQL databases is one of the potential options for storing and processing big data lakes. However, searching for large data in No-SQL databases is a complex and time-consuming task. Further, information r...
详细信息
the use of No-SQL databases is one of the potential options for storing and processing big data lakes. However, searching for large data in No-SQL databases is a complex and time-consuming task. Further, information retrieval from big data management suffers in terms of execution time. To reduce the execution time during the search process, we propose a fast and suitable approach based on the quantum Grover algorithm, which represents one of the best-known approaches for searching in an unstructured database and resolves the unsorted search query in O (root n) time complexity. To assess our proposal, a comparative study with linear and binary search algorithms was conducted to prove the effectiveness of Grover's algorithms. Then, we perform extensive experiment evaluations based on ibm_qasm_simulator for searching one item out of eight using Grover's search algorithm based on three qubits. The experiments outcomes revealed encouraging results, with an accuracy of 0.948, well in accordance with the theoretical result. Moreover, a discussion of the sensitivity of Grover's algorithm through different iterations was carried out. Then, exceeding the optimal number of iterations round (pi/4 root N), induces low accuracy of the marked state. Furthermore, the incorrect selection of this parameter can outline the solution.
The natural gradient (NG) is an information-geometric optimization method that plays a crucial role, especially in the estimation of parameters for machine learning models like neural networks. To apply NG to quantum ...
详细信息
The natural gradient (NG) is an information-geometric optimization method that plays a crucial role, especially in the estimation of parameters for machine learning models like neural networks. To apply NG to quantum systems, the quantum natural gradient (QNG) was introduced and utilized for noisy intermediate-scale devices. Additionally, a mathematically equivalent approach to QNG, known as the stochastic reconfiguration method, has been implemented to enhance the performance of quantum Monte Carlo methods. It is worth noting that these methods are based on the symmetric logarithmic derivative (SLD) metric, which is one of the monotone metrics. So far, monotonicity has been believed to be a guiding principle to construct a geometry in physics. In this paper we propose generalized QNG by removing the condition of monotonicity. Initially, we demonstrate that monotonicity is a crucial condition for conventional QNG to be optimal. Subsequently, we provide analytical and numerical evidence showing that nonmonotone QNG outperforms conventional QNG based on the SLD metric in terms of convergence speed.
Compared with off-line digital signal processing (DSP) verification, achieving the expected performance and hardware efficiency in application specific integrated circuit (ASIC) is more critical for DSP to reduce powe...
详细信息
Compared with off-line digital signal processing (DSP) verification, achieving the expected performance and hardware efficiency in application specific integrated circuit (ASIC) is more critical for DSP to reduce power consumption and cost. The performance of traditional frequency offset compensation algorithms based on feedforward structure is strongly dependent on the accuracy of frequency offset estimation. Therefore, frequency offset calculation and loop filtering implemented in ASIC or field programmable gate array (FPGA) usually choose high word-width fixed-point or floating-point operations, which increase the consumption of logical resources and reduce the clock frequency that hardware logic can achieve. This work proposes a frequency offset compensation scheme based on polar coordinate processing and feedback structure, and a pre-decision-based angle differential estimator is used to estimate the residual frequency offset. In the proposed feedback structure, the frequency offset estimator is realized by a simple accumulator, and the input of the accumulator is the residual frequency offset or its scaling, which will reduce the requirement for the accuracy of the residual frequency offset estimator. The offline verification results show that the performance of the proposed algorithm is close to that of the traditional algorithm, but the proposed algorithm has lower logic resource consumption and higher clock frequency in hardware implementation based on FPGA. The performance of the proposed method is evaluated in real-time through 10-Gbps data rate polarization-multiplexed quadrature phase shift keying modulation after 20-km standard single-mode fiber transmission. Compared with offline processing in MATLAB (R), no hardware implementation penalty is observed.
Post quantum cryptography are defined as public key crypto algorithms whose pub- lic keys are generated from hard computational problems that are complex to solve in polynomial time by a quantum computer given worst c...
Post quantum cryptography are defined as public key crypto algorithms whose pub- lic keys are generated from hard computational problems that are complex to solve in polynomial time by a quantum computer given worst case instances. The hard problems which have been proven to be quantum resistant include the shortest vec- tor problem of lattices, the syndrome decoding problem of certain error correcting codes and the isomorphism of polynomial problem of multivariate quadratic poly- nomials. Solutions to these problems have been proposed which in turn have impact on the security and storage cost of such algorithms to protect information systems in the future. In this thesis, alternative solutions are proposed which are based on robust and complex vector space mappings. Firstly, Dimensionality mapping is pro- posed to reduce the basis into its linear independent vectors at low dimensionality by constructing a collapse function as an optimization problem. This optimization problem can be solved on the condition that a projection of the basis vectors from the High dimensional space to low dimensional manifold would have nearly orthogonal constitution. These eliminates the need for pre-processing using Gram-Schmidt Or- thogonalization process. Implementing this approach on a channel basis, showed an improved BER performance over the Lenstra-Lenstra-Lovatsz algorithm for about 1db and 4db in the 4 × 4 and 6 × 6 uncoded system using 4QAM constellation. Secondly, the solution of the syndrome decoding problem is generalized to codes associated with the totally non-negative Grassmannian. The solution was reduced to an instance of finding a subset of the Plucker coordinates with the minimum Grassmann distance from the subspace containing the encrypted message symbols. Furthermore, bounds where derived which showed that the complexity scales up on the size of the Plucker coordinates. In addition, experimental results on decoding failure probability and complexity based on row op
暂无评论