共查询到20条相似文献,搜索用时 15 毫秒
1.
Yaakov S. Weinstein 《Quantum Information Processing》2016,15(3):1263-1271
In this work, we explore the accuracy of quantum error correction depending of the order of the implemented syndrome measurements. CSS codes require that bit-flip and phase-flip syndromes be measured separately. To comply with fault-tolerant demands and to maximize accuracy, this set of syndrome measurements should be repeated allowing for flexibility in the order of their implementation. We examine different possible orders of Shor-state and Steane-state syndrome measurements for the [[7,1,3]] quantum error correction code. We find that the best choice of syndrome order, determined by the fidelity of the state after noisy error correction, will depend on the error environment. We also compare the fidelity when syndrome measurements are done with Shor states versus Steane states and find that Steane states generally, but not always, lead to final states with higher fidelity. Together, these results allow a quantum computer programmer to choose the optimal syndrome measurement scheme based on the system’s error environment. 相似文献
2.
We present a scheme for asymmetric multi-party quantum state sharing of an arbitrary m-qubit state with n agents. The sender Alice first shares m − 1 Bell states and one n + 1-particle Greenberger–Horne–Zeilinger state with n agents, where the agent Bob, who is designated to recover the original m-qubit state, just keeps m particles and other agents (all controllers) n − 1 particles, that is, each controller only holds one particle in hand. Subsequently, Alice performs m Bell-basis measurements on her 2m particles and each controller only need take a single-particle measurement on his particle with the basis X. Finally, Bob can recover the original m-qubit state with the corresponding local unitary operations according to Alice and all controllers’ measurement results. Its intrinsic efficiency for qubits approaches 100%, and the total efficiency really approaches the maximal value, which is higher than those of the known symmetric schemes. 相似文献
3.
Yaakov S. Weinstein 《Quantum Information Processing》2011,10(4):533-542
In this paper I explore the entanglement evolution of qubits that are part of a five qubit quantum error correction code subject
to various decohering environments. Specifically, I look for possible parallels between the entanglement degradation and the
fidelity of the logical qubit of quantum information stored in the physical qubits. In addition, I note the possible exhibition
of entanglement sudden death (ESD) due to decoherence and question whether ESD is actually a roadblock to successful quantum
computation. 相似文献
4.
We show how to convert an arbitrary stabilizer code into a bipartite quantum code. A bipartite quantum code is one that involves two senders and one receiver. The two senders exploit both nonlocal and local quantum resources to encode quantum information with local encoding circuits. They transmit their encoded quantum data to a single receiver who then decodes the transmitted quantum information. The nonlocal resources in a bipartite code are ebits and nonlocal information qubits, and the local resources are ancillas and local information qubits. The technique of bipartite quantum error correction is useful in both the quantum communication scenario described above and in fault-tolerant quantum computation. It has application in fault-tolerant quantum computation because we can prepare nonlocal resources offline and exploit local encoding circuits. In particular, we derive an encoding circuit for a bipartite version of the Steane code that is local and additionally requires only nearest-neighbor interactions. We have simulated this encoding in the CNOT extended rectangle with a publicly available fault-tolerant simulation software. The result is that there is an improvement in the “pseudothreshold” with respect to the baseline Steane code, under the assumption that quantum memory errors occur less frequently than quantum gate errors. 相似文献
5.
We present a new scheme for sharing an arbitrary two-qubit quantum state with n agents. In our scheme, the sender Alice first shares n Einsein-Podolsky-Rosen (EPR) pairs in Bell states with n agents. After setting up the secure quantum channel, Alice first applies (n − 2) Controlled-Not (CNOT) gate operations, and then performs two Bell-state measurements and (n − 2) single-particle measurements (n >2). In addition, all controllers only hold one particle in their hands, respectively, and thus they only need to perform a single-particle measurement on the respective particle with the basis {|0?, |1?}{{{vert}0rangle, {vert}1rangle}}. Compared with other schemes with Bell states, our scheme needs less qubits as the quantum resources and exchanges less classical information, and thus obtains higher total efficiency. 相似文献
6.
Li Dong Jun-Xi Wang Hong-Zhi Shen Dan Li Xiao-Ming Xiu Ya-Jun Gao X. X. Yi 《Quantum Information Processing》2014,13(6):1413-1424
We present two error-tolerance transmission protocols of a single-photon polarization state when bit-flip error is taken into account. For achieving the transmission target of the single-photon state, the first protocol needs to encode it to a nonmaximally entangled Bell state. Exploiting the interaction of the polarization entanglement with spatial entanglement between two photons, its success probability is 100 %. Different from the first protocol, the second one utilizes the idea of teleportation with an auxiliary Bell state. By performing quantum nondemolition measurement to analyze the parity, conventional measurement, and unitary transformation operations, the success probability of the second protocol is approximately unity. Furthermore, the second protocol can be generalized to the error-tolerance transmission of an arbitrary mixed state or the distribution of an arbitrary multi-photon entangled state. 相似文献
7.
ZHONG ShuQin MA Zhi & XU YaJie Zhengzhou Institute of Information Engineering University of Information Engineering of China Zhengzhou China 《中国科学:信息科学(英文版)》2010,(3):515-523
We present a systematic way to construct p-ary quantum error correcting codes using logic functions. As a consequence, for a given function with APC distance d′ 2, we can construct quantum codes with parameters ((n, K, d))p and gain a lower bound of K for all 2 d d′. The basic states of the constructed quantum codes can be stated and the sufficient conditions for saturating quantum Singleton bound are also discussed. We give quantum codes [[5, 1, 3]]p with p prime, [[6, 0, 4]], [[6, 2, 3]]p with p > 2 prime... 相似文献
8.
We present a scheme for joint remote implementation of an arbitrary single-qubit operation following some ideas in one-way quantum computation. All the senders share the information of implemented quantum operation and perform corresponding single-qubit measurements according to their information of implemented operation. An arbitrary single-qubit operation can be implemented upon the remote receiver’s quantum system if the receiver cooperates with all the senders. Moreover, we study the protocol of multiparty joint remote implementation of an arbitrary single-qubit operation with many senders by using a multiparticle entangled state as the quantum channel. 相似文献
9.
Zhiguo Qu Shengyao Wu Mingming Wang Le Sun Xiaojun Wang 《Quantum Information Processing》2017,16(12):306
As one of important research branches of quantum communication, deterministic remote state preparation (DRSP) plays a significant role in quantum network. Quantum noises are prevalent in quantum communication, and it can seriously affect the safety and reliability of quantum communication system. In this paper, we study the effect of quantum noise on deterministic remote state preparation of an arbitrary two-particle state via different quantum channels including the \(\chi \) state, Brown state and GHZ state. Firstly, the output states and fidelities of three DRSP algorithms via different quantum entangled channels in four noisy environments, including amplitude-damping, phase-damping, bit-flip and depolarizing noise, are presented, respectively. And then, the effects of noises on three kinds of preparation algorithms in the same noisy environment are discussed. In final, the theoretical analysis proves that the effect of noise in the process of quantum state preparation is only related to the noise type and the size of noise factor and independent of the different entangled quantum channels. Furthermore, another important conclusion is given that the effect of noise is also independent of how to distribute intermediate particles for implementing DRSP through quantum measurement during the concrete preparation process. These conclusions will be very helpful for improving the efficiency and safety of quantum communication in a noisy environment. 相似文献
10.
By using the \(\chi \) -type entangled states, a novel scheme for multi-party quantum state sharing (MQSTS) of an arbitrary multi-qubit state is investigated. It is shown that the MQSTS scheme can be faithfully realized by performing appropriate Bell state measurements, Z basis measurements and local unitary operations, rather than multi-qubit entanglement or multi-particle joint measurements. Thus, our MQSTS scheme is more convenient in a practical application than some previous schemes. Furthermore, its intrinsic efficiency for qubits approaches 100 %, and the total efficiency really approaches the maximal value, which is higher than those of the previous MQSTS schemes. Finally, we analyze the security from the views of participant attack and outside attack in detail. 相似文献
11.
12.
Debjit Ghosh Pratik Agarwal Pratyush Pandey Bikash K. Behera Prasanta K. Panigrahi 《Quantum Information Processing》2018,17(6):153
Construction of a fault-tolerant quantum computer remains a challenging problem due to unavoidable noise and fragile quantum states. However, this goal can be achieved by introducing quantum error-correcting codes. Here, we experimentally realize an automated error correction code and demonstrate the nondestructive discrimination of GHZ states in IBM 5-qubit quantum computer. After performing quantum state tomography, we obtain the experimental results with a high fidelity. Finally, we generalize the investigated code for maximally entangled n-qudit case, which could both detect and automatically correct any arbitrary phase-change error, or any phase-flip error, or any bit-flip error, or combined error of all types of error. 相似文献
13.
We present an innovative and extremely efficient scheme to share an arbitrary multi-qubit state between n agents with only 1 GHZ channel under control of m agents in a network. Compared with existing ones in this literature, our scheme requires less communication resources, least qubits and only three physical favorable simple operations (single-qubit measurement, Bell-basis measurement and CNOT gate operations) are included, leading to a higher overall efficiency. 相似文献
14.
Kui Hou Guo-Hong Liu Xue-Yong Zhang Shou-Qi Sheng 《Quantum Information Processing》2011,10(4):463-473
We present an efficient scheme for five-party quantum state sharing (QSTS) of an arbitrary m-qubit state with multiqubit cluster states. Unlike the three-partite QSTS schemes using the same quantum channel [Phys. Rev. A 78, 062333 (2008)], our scheme for sharing of quantum information among five parties utilizing a cluster state as an entangled resource. It is found that the six-partite cluster state can be used for QSTS of an entangled state, the five-partite cluster state can be used for QSTS of an arbitrary two-qubit state and also can be used for QSTS of an arbitrary m-qubit state. It involves two-qubit Bell-basis or three-qubit GHZ-basis measurements, not multipartite joint measurements, which makes it more convenient than some previous schemes. In addition, the total efficiency really approaches the maximal value. 相似文献
15.
16.
Le Sun Shengyao Wu Zhiguo Qu Mingming Wang Xiaojun Wang 《Quantum Information Processing》2018,17(10):283
Multi-particle quantum state deterministic remote preparation is a fundamental and important technical branch in quantum communication. Since quantum noise is unavoidable in realistic quantum communication, it is important to analyze the effect of noise on multi-particle quantum communication protocols. In this paper, we study the effects of noise, such as amplitude damping, phase damping, bit-flip and depolarizing noises, on two deterministic remote preparation of an arbitrary three-particle state protocols, which are based on two different entangled channels, namely \(\chi \) state and Brown state. The detailed mathematical analysis shows that the output states of two deterministic remote state preparation (DRSP) protocols are the same in the same noisy environment. That is to say, in the same noisy environment, the effects of noise on two DRSP protocols are the same. This conclusion proves that these two DRSP protocols will produce the same arbitrary three-particle states in the same noise channel environment, and so that these protocols are inherently convergent and can be substituted for each other in certain circumstances. In addition, this paper also takes three-particle states \(a\left| {000} \right\rangle + b{\mathrm{e}^{ic}}\left| {111} \right\rangle \) as an example and studies the relationship between the fidelity, the target state and the size of the noise factor. The results show that if the target state can be selected, an appropriate target state can effectively resist on the bit-flip noise. If the target state cannot be selected, as the increase in the size of noise factor, the fidelities of the two DRSP schemes in the amplitude damping noise and phase damping noise are always larger than those in the bit-flip noise and depolarizing noise. This conclusion indicates that two protocols have better resistance on amplitude damping and phase damping noise than the bit-flip and depolarizing noises. These findings and analyses will provide valid help in deterministic remote preparation of an arbitrary three-particle state in a noisy environment. 相似文献
17.
Hai-Sheng Li Qingxin Zhu Ri-Gui Zhou Lan Song Xing-jiang Yang 《Quantum Information Processing》2014,13(4):991-1011
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 $1024 \times 1024 \times 1024$ needs $1024 \times 1024 \times 1024 \times 24$ 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 $(n\,+\,1)$ -qubit normal arbitrary quantum superposition state (NAQSS), where $n$ qubits represent colors and coordinates of ${2^n}$ pixels (e.g., represent a three-dimensional color image of $1024 \times 1024 \times 1024$ 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 $O(\sqrt{N/r} )$ where $N$ and $r$ are the numbers of pixels of an image and a target sub-image, respectively. 相似文献
18.
In the paper, the problem of simulation of quantum error correction by means of error correcting codes is discussed. Examples of error correction by means of quantum circuits constructed with the help of the QuantumCircuit package written in the language of the computer algebra system Mathematica are presented. 相似文献
19.
This paper proposes a novel scheme named CodeHop, which provides both information reliability and security using code hop ping based on low-density parity-check (LDPC) codes. In contrast to traditional systems that perform error correction and encryption at different layers, CodeHop combines these two operations into a single step at physical layer, such that each plaintext message is jointly encoded and encrypted by a hopping parity-check matrix. According to a pseudo-random number generator (PRNG), the hopping matrix may rapidly switch among a sequence of LDPC parity-check matrices, which is randomly generated by a structured-random protograph expanding technique. Simulations show that reliable communication can be achieved by CodeHop with good error-correcting performance. In the meantime, CodeHop may improve the security of traditional systems such as GSM. Taking the A5/1 stream cipher used in GSM as the PRNG, it is shown that CodeHop is resistant to existing chosen-plaintext attacks that break A5/1 cipher already. Moreover, the security of CodeHop will be enhanced in the presence of channel errors as well. 相似文献
20.
Yi-you Nie Yuan-hua Li Jun-chang Liu Ming-huang Sang 《Quantum Information Processing》2011,10(5):603-608
We demonstrate that a four-qubit cluster state can be used to realize the deterministic quantum state sharing (QSTS) of an
arbitrary four-qubit GHZ-type state among three parties by introducing three ancillary qubits and performing three controlled-NOT
operations. In our scheme, any one of the two agents has the ability to reconstruct the original state if he/she collaborates
with the other one, whilst individual agent obtains no information. 相似文献