Quantum Information Processing最新文献

Quantum secret sharing holds an important place in quantum cryptography. In this paper, a threshold changeable dynamic quantum secret sharing scheme with cheating identification is firstly proposed based on the Chinese Remainder Theorem. On the premise of not altering the shared secret and the private shares of the original participants, our scheme realizes the dynamic updating of participants and for the first time achieves the changeable threshold in the quantum environment, which greatly improves the flexibility and practicality of the scheme. In addition, we generalize the entanglement swapping equations of Bell states in 2-dimension to d-dimension. During the reconstruction phase, our scheme can timely detect and identify the cheating behaviors based on the randomized components and the entanglement swapping equations of d-dimensional Bell states. Meanwhile, the randomized components ensure privacy protection for shares and avoid the interference of invalid shares when recovering the secret. Security analysis shows that our scheme is resistant to not only a series of typical external attacks but also forgery, collusion, and dishonest revoked participant attacks. Compared with the existing schemes, our scheme is not only more secure and efficient but also has lower computational consumption.

A few years ago Hong et al.  (Quantum Inf Process 16:236, 2017) proposed a quantum identity authentication protocol using single photons and executable on currently available quantum hardware. Zawadzki later published two attacks on this protocol, and suggested a mitigation in the same work. In this comment we point out an additional vulnerability that causes the prover Alice to leak a percentage of her secret key at every authentication attempt. The latter is due to a problematic policy in the generation and management of decoy states. We conclude by showing a simple mitigation that addresses the issue.

While Grover’s search algorithm is asymptotically optimal, it does not always result in a real solution. If the search fails, the algorithm must be ran again from the beginning, conditionally doubling the effective number of oracle calls. Previous research attempted to fix this issue by modifying the oracle or alternating between numerically optimized reflectors. In this paper, we present an optimal initial state and reflector that produce an exact search with Grover’s algorithm at the cost of at most one additional oracle call beyond the optimum, a cost which can be nullified if we know a non-solution. We do this without modifying the oracle, without changing the diffuser at each step and even without any numerical optimization procedure required.

In this article, we tackle the aircraft load optimization problem using classical optimization algorithms and optimization algorithms with QUBO (quadratic unconstrained binary optimization) formulation to run on quantum annealers. The problem is realistic based on plans of a certain aircraft model, the Airbus A330 200F, and can be adapted to other models from other manufacturers. We maximize a characteristic of the combination of containers (unit load device, ULD) to be transported, be it weight, volume, profit, or another, while complying with necessary parameters related to the flight such as the balance of the center of gravity as well as stress in the structure. Finally, examples of the results of different runs on QUBO in the D-Wave simulator are presented.

The paper addresses the construction of an error correction code for quantum computations based on squeezed Fock states. It is shown that the use of squeezed Fock states makes it possible to satisfy the Knill-Laflamme (KL) criteria for bosonic error correction codes. It is shown that the first squeezed Fock state corrects both particle loss and dephasing errors better than higher-order states. A comparison of the proposed code with a code based on the squeezed Schrodinger’s cat states is carried out on the basis of the KL cost function. Using this function, we show that the squeezed first Fock state is competitive in protecting information in a channel with particle loss and dephasing.

This paper introduces a bidirectional quantum controlled teleportation (BQCT) protocol within a multi-hop communication network, designed to teleport an arbitrary (n)-qubit state through an (m)-hop network framework. Utilizing the IBM Quantum (IBMQ) Experience simulation framework and the Qiskit library, we empirically substantiate the protocol's efficacy. Our findings indicate consistent teleportation across varying hop counts, though the precision of the output state diminishes with an increase in hops. This research further delves into the impact of quantum noise—namely amplitude-damping, phase-damping, bit-flip, and phase-flip—on the protocol's performance. A significant finding is that the detrimental effects of quantum noise escalate with the number of hops, with noise influence showing independence from the input state and causing an exponential decrease in output state fidelity. Thus, our analysis suggests a potential for optimizing real quantum communication systems through a balance between error reduction strategies and the maximum tolerable noise level.

An asymmetric bidirectional quantum teleportation scheme was proposed by utilizing a seven-qubit entangled state as quantum channel. The scheme can perfectly achieve the transmission of a three-qubit target entangled state from one legitimate user Alexis to the other legitimate user Billy. Simultaneously, another two-qubit target entangled state can be reversibly conveyed from Billy to Alexis. The implementation of the scheme requires only Bell-state measurements and some simple necessary quantum operations. The impact of phase-damping noise on our scheme is investigated by calculating and discussing its fidelity. Compared with some analogous schemes, the proposed scheme has many significant advantages, such as less quantum and classical resources consumed, higher intrinsic efficiency, lower execution difficulty. Furthermore, it has strong compatibility and experimental feasibility.

We propose a new non-Gaussian version of the continuous variables measurement device independent quantum key distribution (CV-MDI-QKD) protocol by utilizing a photon added-then-subtracted (PAS) state. We report that our single- and two-mode PAS-CV-MDI-QKD protocols outperform pure state CV-MDI-QKD protocol when considering weak squeezing and high noise, which is the practical regime. With such resources, CV-MDI-QKD is inaccessible when using a pure TMSV state, while PAS-CV-MDI-QKD can generate a useful key rate in this regime. We also compare PAS-CV-MDI-QKD with a two-mode photon replaced (2PR) state, which was not studied in low squeezing for MDI-QKD before.

Most of the previous quantum private query protocols are based on the BB84 key distribution type and generally use a method that wastes most quantum resources to complete security detection. In order to save resources, this paper proposes a noiseless counterfactual quantum private query protocol with high efficiency. This protocol improves the counterfactual quantum key distribution protocol proposed by Rao and Srikanth (Phys Rev A 104:022424, 2021. https://doi.org/10.1103/PhysRevA.104.022424). The communicating parties randomly select quantum bits with probability f to perform flipping to complete the quantum private query. The detector at the sending end receives the counterfactual bit, which we use for security detection; the detector at the receiving end is called a non-counterfactual bit, which is combined with random bit flipping to realize key transmission, followed by traditional post-processing and private query. Finally, when (f=0.5), the response probability (keys rate) of the non-counterfactual detector at the receiving end can reach a minimum value of 0.5.

As large language models (LLMs) continue to expand in complexity, their size follows an exponential increase following Moore’s law. However, implementing such complex tasks with LLMs poses a significant challenge, as classical computers may lack the necessary space to run or store the model parameters. In this context leveraging the principles of hybrid quantum machine learning for language models offers a promising solution to mitigate this issue by reducing storage space for model parameters. Although pure quantum language models have demonstrated success in recent past, they are constrained by limited features and availability. In this research we propose the DeepKet model an approach with a quantum embedding layer, which utilizes the Hilbert space generated by quantum entanglement to store feature vectors, leading to a significant reduction in size. The experimental analysis evaluates the performance of open-source pre-trained models like Microsoft Phi and CodeGen, specifically fine-tuned for generating Prolog code for geo-spatial data retrieval. Furthermore, it investigates the effectiveness of quantum DeepKet embedding layers by comparing them with the total parameter count of traditional models.