Quantum Information Processing最新文献

We have proposed several single-qubit phase gates with two quantum dots (QDs) embedded in a T-type plasmonic waveguides (PWs), wherein binary qubits are encoded by frequency of photons. Our results reveal that in such a hybrid system, an arbitrary single-qubit phase shift gates can be achieved and the gate performance could be controlled by adjusting spacing distance between two QDs and frequency detuning in a proper manner. We show that the phase of outstate can be adequately adjusted by distance between two QDs and the detuning could cause a phase shift. We investigated schemes theoretically via the real-space approach and estimated the feasibilities of them by evaluating fidelities for several parameters. Under the present technology and high fidelities, the proposed one could be utilized for quantum computation and quantum information processing.

The Eisert–Wilkens–Lewenstein (EWL) game can be used to solve the quantum prisoner’s dilemma is investigated. It is assumed that the states of the players are polarized in different directions, and the entangling gate is time dependent, with interaction strength represented by linear, sine, cosine, or exponential functions. If both players cooperate, the payoffs remain above their classical counterparts. However, if they do not cooperate, the payoff for one player increases at the expense of the other. The payoffs of both players are similar when their states are prepared with the same settings, whereas different settings for the initial states result in different payoffs. Due to the periodic nature of the interaction strength, the payoffs oscillate between their classical bounds when both initial states have the same settings. Conversely, for different initial state, the upper bounds are lower than the classical ones, while the minimum values remain above their corresponding classical payoffs.

The structures of nonlocal sets of orthogonal product states are of great significance to understanding the essence of quantum nonlocality. Recently, Zhen et al. [Phys. Rev. A 106:062432, 2022] propose general constructions of nonlocal sets with smaller size in multipartite systems. In this paper, we first give a novel method to construct a nonlocal set of orthogonal product states in ((mathbb {C}^{d})^{otimes n}) quantum systems for (dge 3) and (nge 3). The new set has the same number of elements with zhen et al.’s set in a same quantum system while its structure is different from that of zhen et al.’s set. Then, we generalize this construction method to (otimes _{i=1}^{n}mathbb {C}^{d_{i}}) quantum system and construct a nonlocal set of states with (sum _{j=1}^{n-2} d_{j}+2d_{n}-n+1) members which is lower than that of zhen et al.’s set, where (3le d_{1}le d_{2}le cdots le d_{n}). Comparing with the previous works, the nonlocal sets we constructed have fewer elements and good symmetric properties. This contributes to further research on the structures of nonlocal sets in multipartite systems.

This research explores the application of quantum computing to DNA analysis, focusing on transitioning classical data to quantum information formats. We developed the Quantum Cache Memory (QCM) framework, which utilizes superposition and hybrid encoding via entanglement. The QCM framework is designed to preserve the integrity of genetic sequences throughout the quantum computing process. The effectiveness of this approach is demonstrated through implementations of single nucleotide polymorphism (SNP) detection and pattern search algorithms using a perfect quantum simulator. The results demonstrate the potential for leveraging quantum phenomena to process classical data in parallel on quantum hardware. However, the limitations of current quantum hardware and data encoding efficiency are acknowledged. This study shows the groundwork for future improvements in quantum computing ecosystems, such as the need for persistent quantum states and more effective handling of large-scale data. Our research has been conducted solely through simulations and mathematical modeling, indicating the necessity for future work on actual quantum servers.

Preparing quantum state remotely is one of the central tasks in long-distance quantum communication. Here we present a protocol to parallel remote preparation of the arbitrary single-qubit states in three DoFs by rotating quantum states in each DoF of the photon via linear-optical elements. The arbitrary single-qubit states can be remote prepared in frequency, time-bin and polarization DoFs by manipulating the quantum states in each DoF. Moreover, we discuss the protocol for parallel remote preparation in frequency, time-bin and polarization DoFs by using partially hyperentangled state as the quantum channel. Our protocols have the advantages of having higher channel capacity than previous RSP protocols since each photon can carry 3 qubits of quantum information via a fiber channel, not just 1 or 2 qubits. Since partially hyperentangled channel can be transformed to the target channel for parallel remote state preparation recursively via optical elements, the efficiency for hyperentangled channel is greatly enhanced.

The measurement-based quantum computing (MBQC) is another universal quantum computing model, different from the conventional quantum circuit model. MBQC employs measurements on designated qubits in entangled states to perform universal computation. As theoretical research and experimental techniques advance in recent years, applications grounded in MBQC have progressively emerged. This article endeavors to encapsulate the nascent application domains of MBQC. We start with a brief introduction to the fundamental principles of the model with an emphasis on the comparison between MBQC and circuit-based quantum computing (CBQC). Then, the unique advantages of MBQC are highlighted, such as an explicit and intuitive physical intention, robust algorithm construction, superior single-qubit quantum measurement fidelity, efficient information flow transmission, and so on. Based on these merits, we next introduce the gradually emerging applications of MBQC in diverse areas, representatively including quantum algorithms and quantum networks. In the end, we present an overview of the up-to-date state of software and hardware infrastructure that supports applied research. We hope this review could be useful to people unfamiliar with the field and can also serve as a reference for those within it.

Quantum information and quantum computation have become a hot topic in recent decades. Quantum error-correcting codes are useful and have many applications in quantum computations and quantum communications. We construct a new class of quantum Maximum Distance Separable (MDS) codes. Our construction is based on a recent result of Ball and Vilar (IEEE Trans Inf Theory 68:3796–3805, 2022). We study a large class of explicit polynomials and obtain their required arithmetical properties which imply construction of new q-ary quantum MDS codes of length strictly larger than (q+1), when q is odd.

We study the polygamy property in tripartite and multipartite quantum systems. In tripartite system, we build a solution set for polygamy in tripartite system and find a sufficient and necessary condition of the set for continuous measure of quantum correlation Q to be polygamous. In multipartite system, we provide generalized definitions for polygamy in n-qubit systems with (nge 4), and then, we build polygamy inequalities with a polygamy power (beta ). Next we also describe that any entanglement of assistance can be polygamy according to our new definition in multipartite systems. For better understanding, we use right triangle and tetrahedron to explain our new polygamy relations. Moreover, the polygamy relations between each single qubit and its remaining partners are also investigated to enrich our results.

Session keys play an important role in practical communication. In this paper, we propose an efficient dynamic quantum session key agreement protocol based on d-level mutually unbiased bases via multi-party multiplication. In the initial phase, the trusted center detects the identity and number of participants who apply for the construction of session keys by one-to-one correspondence of hash values to avoid any fake attacks. In the encoding phase, all applied participants encrypt their private keys with the system key through location tokens and perform the unitary operation to encode the encryption results on a sequence of mutually unbiased basis quantum states and transmit them in the circle type. The security analysis shows that the proposed scheme is resistant to both external and internal attacks. In this paper, with the help of a predefined system key, the quadratic hash over a finite field is successfully applied to identity authentication for the first time, and allows an arbitrary number of participants to construct a session key dynamically, which is more pervasive compared with other schemes.