CN105490750A

CN105490750A - Method for remotely forming two-atom entangled state based on cavity quantum electrodynamics technology

Info

Publication number: CN105490750A
Application number: CN201510819794.9A
Authority: CN
Inventors: 任远; 肖骁琦
Original assignee: Shanghai Dianji University
Current assignee: Shanghai Dianji University
Priority date: 2015-11-23
Filing date: 2015-11-23
Publication date: 2016-04-13

Abstract

The invention provides a method for remotely preparing two-atom entanglement states based on cavity quantum electrodynamics technology. A sender will assist one of the two receivers to establish a two-atom entanglement state of the form |φ＞=α|gg＞+β|ee＞, where |g＞ and |e＞ represent the two-level atoms respectively The ground state and the excited state, the parameters α and β are real numbers, and the condition α ² + β ² = 1 is satisfied; the sender has the information of this quantum state, and the two receivers do not know the information of the quantum state; in order to complete the task of transmitting information , the sender establishes a two-atom entangled state and a three-atom W-like entangled state as a quantum channel between itself and two receivers.

Description

A Method for Remotely Preparing Two-Atom Entangled States Based on Cavity Quantum Electrodynamics Technology

技术领域technical field

本发明涉及量子信息、通信网络、新型光通信技术领域，更具体地说，本发明涉及一种基于腔量子电动力学技术的远程制备两原子纠缠态的方法。The present invention relates to the technical fields of quantum information, communication network, and novel optical communication. More specifically, the present invention relates to a method for remotely preparing two-atom entangled states based on cavity quantum electrodynamics technology.

背景技术Background technique

量子通信是近年来兴起的一种新型通信方式。通过将信息编码于具有量子特性的物理系统，利用系统状态的量子特性，例如量子纠缠、测量塌缩、量子态不可克隆等，使得量子通信过程较经典通信更加的安全，高效，抗干扰。目前人们提出了各种有意思的量子通信方案，例如量子隐形传态，量子秘钥分配，远程态制备，量子秘密共享等。这些通信方案可以在光学系统、核磁共振系统、量子点系统、腔电动力学系统等物理系统中实现。Quantum communication is a new type of communication that has emerged in recent years. By encoding information into a physical system with quantum properties, using the quantum properties of the system state, such as quantum entanglement, measurement collapse, and quantum state non-cloning, etc., the quantum communication process is safer, more efficient, and anti-interference than classical communication. At present, various interesting quantum communication schemes have been proposed, such as quantum teleportation, quantum secret key distribution, remote state preparation, quantum secret sharing, etc. These communication schemes can be implemented in physical systems such as optical systems, nuclear magnetic resonance systems, quantum dot systems, and cavity electrodynamic systems.

在这些系统中，腔QED(quantumelectrodynamics，量子电动力学)系统得到了更多的关注，因为一般来说人们普遍认为原子是比较理想的信息存储器，光子是信息交换的媒介，而腔恰恰为原子和光子的相互作用提供了一个良好的平台。考虑到腔QED独有的优势，人们开始在理论和实验上研究如何在该体系中实现各种量子信息过程[1]-[11]。但是对于量子通信领域中的一个新兴的发展方向——远程态制备，在以往的工作中却涉及不多[12]-[15]。Among these systems, the cavity QED (quantumelectrodynamics, quantum electrodynamics) system has received more attention, because generally speaking, it is generally believed that atoms are ideal information storage, photons are the medium of information exchange, and the cavity is precisely the mechanism for atoms and The interaction of photons provides a good platform. Considering the unique advantages of cavity QED, people began to study theoretically and experimentally how to realize various quantum information processes in this system [1]-[11]. However, for an emerging development direction in the field of quantum communication—remote state preparation, it has not been involved much in previous work[12]-[15].

假设在某些信息处理过程之后，例如，在一次量子秘密共享之后，描述一个秘密量子比特内容的经典信息被拆分并分布于量子网络的不同节点。也就是说，每一个节点只掌握了秘密量子比特态的一部分信息；没有任何一个节点拥有这个秘密量子比特的全部的信息，可以独立地恢复秘密量子比特的信息。现在的问题是如何能够在一个新的节点重建秘密信息。为此提出了多方联合远程制备量子态的方法[1]-[11]。这些方法分别利用了不同的量子纠缠态作为量子信息的传输通道，完成对不同类型的量子比特态的联合远程制备任务。但是，这些研究工作仅仅从数学的层面提出了对量子比特态进行多方联合远程制备的方法，而没有针对具体的物理系统提出在实践中具有可操作性的方案。少数的研究者提出来的实验方案[11][12]都是以单光子作为信息的载体，而单光子在实际的操作中往往很容易受到环境的影响并湮灭。Suppose that after some information processing, for example, after a quantum secret sharing, the classical information describing the content of a secret qubit is split and distributed to different nodes of the quantum network. That is to say, each node only has a part of the information of the secret qubit state; no node has all the information of the secret qubit, and can independently restore the information of the secret qubit. The question now is how to be able to reconstruct the secret information in a new node. For this reason, a multi-party joint remote preparation method for quantum states was proposed [1]-[11]. These methods respectively use different quantum entanglement states as the transmission channel of quantum information to complete the joint remote preparation task of different types of qubit states. However, these research works only proposed a multi-party joint remote preparation method for qubit states from the mathematical level, but did not propose a practically operable solution for specific physical systems. The experimental schemes [11][12] proposed by a small number of researchers all use single photons as information carriers, and single photons are often easily affected by the environment and annihilated in actual operation.

目前对于远程态制备的实验方案，主要是在光子系统进行探讨。虽然光子传输速度快，但是消相干时间短，在实际的物理环境中容易湮灭。并且，远程制备量子态的过程中并不需要将信息的载体进行传输，而是要对信息的载体进行适当的操作。由此可见，光子系统并不是完成远程态制备的理想物理系统。此外，虽然有少数基于原子纠缠态的远程态制备实验方案，但其中大部分的方案都仅限于一位发送者和一位接受者，而目前量子通信正在向网络化的方向发展，通信协议需要考虑到有多位参与者的情况。At present, the experimental scheme for remote state preparation is mainly discussed in the photonic system. Although the photon transmission speed is fast, the decoherence time is short, and it is easy to annihilate in the actual physical environment. Moreover, in the process of remote preparation of quantum states, it is not necessary to transmit the information carrier, but to properly operate the information carrier. It can be seen that the photonic system is not an ideal physical system for the preparation of remote states. In addition, although there are a few experimental schemes for remote state preparation based on atomic entanglement states, most of them are limited to one sender and one receiver. At present, quantum communication is developing towards the network, and the communication protocol requires Consider the case where there are multiple participants.

<参考文献><references>

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发明内容Contents of the invention

本发明所要解决的技术问题是针对现有技术中存在上述缺陷，提供一种能够从实际的可操作性出发，提出由一个多方参与的，以两能级原子作为信息的载体，利用两能级原子与经典电磁场之间的相互作用，通过一个三原子W型纠缠态和一个量原子纠缠态组成的量子信息传输信道，完成对两原子量子比特态的远程态制备的方法。The technical problem to be solved by the present invention is to address the above-mentioned defects in the prior art, and to provide a method that can start from the actual operability and propose a multi-party participation, with two-level atoms as the carrier of information, using two-level The interaction between the atom and the classical electromagnetic field, through a quantum information transmission channel composed of a three-atom W-type entangled state and a quantum-atom entangled state, completes the method of remote state preparation for two-atom qubit states.

为了实现上述技术目的，根据本发明，提供了一种基于腔量子电动力学技术的远程制备两原子纠缠态的方法，其中一位发送者将协助两位接收者中的一位建立|φ＞＝α|gg＞+β|ee＞形式的两原子纠缠态，其中|g＞和|e＞分别表示两能级原子的基态和激发态，参数α和β为实数，且满足条件α²+β²＝1；发送者掌握着这个量子态的信息，两位接收者不知道量子态的信息；为了完成传送信息的任务，发送者在其和两位接收者之间建立起一个两原子纠缠态和一个三原子W类纠缠态作为量子信道In order to achieve the above technical purpose, according to the present invention, a method for remotely preparing two-atom entangled states based on cavity quantum electrodynamics technology is provided, wherein one sender will assist one of the two receivers to establish |φ>= Two-atom entangled states of the form α|gg＞+β|ee＞, where |g＞ and |e＞ represent the ground state and excited state of two-level atoms respectively, the parameters α and β are real numbers, and the condition α ² + β is satisfied ² = 1; the sender holds the information of this quantum state, and the two receivers do not know the information of the quantum state; in order to complete the task of transmitting information, the sender establishes a two-atom entanglement state between itself and the two receivers and a triatomic W-like entangled state as a quantum channel

$| | Ψ Ψ > > = = \frac{11}{\sqrt{33}} {((| | e e g g g g > > + + | | g g e e g g > > + + | | g g g g e e > >))}_{11,, 22,, 33},,$

$| | Ψ Ψ > > = = \frac{11}{\sqrt{22}} {((| | g g g g > > + + | | e e e e > >))}_{44,, 55}$

其中原子1和4属于发送者，原子2和3分别属于第一接收者和第二接收者，而原子5交给最终的接收者。Among them, atoms 1 and 4 belong to the sender, atoms 2 and 3 belong to the first receiver and second receiver respectively, and atom 5 is handed over to the final receiver.

优选地，所述的基于腔量子电动力学技术的远程制备两原子纠缠态的方法包括：Preferably, the method for remotely preparing two-atom entangled states based on cavity quantum electrodynamics technology includes:

第一步骤，发送者预先制备一个单模腔A，其中腔场的频率与两能级原子的跃迁频率之间的失谐量为δ，原子-腔耦合系数为ε；同时引入一个强经典场驱动原子，经典场的频率与原子跃迁频率相同，经典场的拉比频率为Ω；发送者设置各器件的参数满足条件Ω＞＞δ＞＞ε，随后将原子1和原子4注入单模腔A，发送者根据所拥有的被传送量子态的信息，控制原子飞行时间τ，使其满足条件同时，调节经典场的拉比频率满足条件Ωτ＝π；In the first step, the sender prepares a single-mode cavity A in advance, in which the mismatch between the frequency of the cavity field and the transition frequency of the two-level atoms is δ, and the atom-cavity coupling coefficient is ε; at the same time, a strong classical field is introduced Drive the atoms, the frequency of the classical field is the same as the atomic transition frequency, and the Rabi frequency of the classical field is Ω; the sender sets the parameters of each device to meet the condition Ω>>δ>>ε, and then injects atoms 1 and 4 into the single-mode cavity A. The sender controls the atomic flight time τ according to the information of the transmitted quantum state, so that it satisfies the condition At the same time, adjusting the Rabi frequency of the classical field satisfies the condition Ωτ=π;

第二步骤，完成第一步骤后，三个原子所组成的系统的量子态将演化至如下形式：The second step, after completing the first step, the quantum state of the system composed of three atoms will evolve to the following form:

$\begin{matrix} | | Ψ Ψ > > = = \frac{11}{66} [[| | g g g g {> >}_{11,, 44} {((- - i i β β | | g g g g e e > > + + α α | | e e g g g g > > + + α α | | g g e e g g > >))}_{22,, 33,, 55} \\ + + | | g g e e {> >}_{11,, 44} {((- - i i β β | | g g g g g g > > + + α α | | e e g g e e > > + + α α | | g g e e e e > >))}_{22,, 33,, 55} \\ + + | | e e g g {> >}_{11,, 44} {((α α | | g g g g g g > > - - i i β β | | e e g g e e > > - - i i β β | | g g e e e e > >))}_{22,, 33,, 55} \\ + + | | e e e e {> >}_{11,, 44} {((α α | | g g g g e e > > - - i i β β | | e e g g g g > > - - i i β β | | g g e e g g > >))}_{22,, 33,, 55}]] \end{matrix}$

此时，发送者分别对其所拥有的原子1和原子4进行测量，判断原子处于基态|g＞还是激发态|e＞；At this time, the sender measures the atom 1 and atom 4 it owns respectively, and judges whether the atom is in the ground state |g> or the excited state |e>;

第三步骤，发送者在两位接收者中选择一位作为最终的接收者，将原子1和原子4的测量结果通过经典信道发送给第一发送者和第二发送者，并将原子5分配给最终的接收者；In the third step, the sender selects one of the two receivers as the final receiver, sends the measurement results of atom 1 and atom 4 to the first sender and the second sender through the classical channel, and assigns atom 5 to the ultimate recipient;

第四步骤，另一位接收者对自己手中的原子进行测量，并将测量结果通过经典信道告知最终的接收者；In the fourth step, another receiver measures the atoms in his hand, and informs the final receiver of the measurement result through the classical channel;

第五步骤，最终的接收者根据来自发送者和另一位接收者的经典信息，判断是否完成了远程态制备的任务。In the fifth step, the final receiver judges whether the task of remote state preparation has been completed according to the classic information from the sender and another receiver.

优选地，第五步骤包括：如果另一位接收者的原子处于激发态|e＞，则最终的接收者不重建被传送量子态。Preferably, the fifth step comprises: the final recipient does not reconstruct the transmitted quantum state if the atom of another recipient is in an excited state |e>.

优选地，第五步骤包括：如果另一位接收者的原子处于基态|g＞，则最终的接收者通过单原子操作，完成远程态制备的任务Preferably, the fifth step includes: if the atom of another recipient is in the ground state |g>, the final recipient completes the task of remote state preparation through single-atom operation

进一步优选地，若发送者的原子处于|ge＞1，4或|eg＞1，4态，则最终的接收者直接得到被传送量子态；Further preferably, if the sender's atom is in the |ge>1,4 or |eg>1,4 state, the final receiver will directly get the transmitted quantum state;

若发送者的原子处于|gg＞1，4或|ee＞1，4态，则最终的接受者利用经典场完成一次单原子操作，以重建被传送量子态。If the sender's atom is in |gg>1, 4 or |ee>1, 4 state, the final recipient will use the classical field to complete a single atomic operation to reconstruct the transmitted quantum state.

本发明提出了一个以两能级原子为信息载体的，涉及到三位参与者的两原子纠缠态的远程态制备方法。该方法中，一位发送者可以将被传送量子态发送给两位接收者中的任意一位，同时另一位接收者扮演了控制者的角色，增加了通信的安全性；该方法涉及到的技术主要是，目前实验上较为成熟的利用腔场与两能级原子相互作用，实现对原子状态进行操控的技术，具有实际的可操作性；同时，采用了三原子W型纠缠态作为量子通道，能够提高通信的抗噪声性能。The invention proposes a two-atom entangled state remote state preparation method that uses two-level atoms as information carriers and involves three participants. In this method, a sender can send the transmitted quantum state to any one of the two receivers, and at the same time, the other receiver plays the role of the controller, which increases the security of communication; the method involves The main technology is that the current experimentally more mature technology of using the interaction between the cavity field and the two-level atoms to realize the manipulation of the atomic state has practical operability; at the same time, the three-atom W-type entangled state is used as the quantum channel, which can improve the anti-noise performance of communication.

附图说明Description of drawings

结合附图，并通过参考下面的详细描述，将会更容易地对本发明有更完整的理解并且更容易地理解其伴随的优点和特征，其中：A more complete understanding of the invention, and its accompanying advantages and features, will be more readily understood by reference to the following detailed description, taken in conjunction with the accompanying drawings, in which:

图1示意性地示出了根据本发明优选实施例的基于腔量子电动力学技术的远程制备两原子纠缠态的方法的流程图。Fig. 1 schematically shows a flowchart of a method for remotely preparing two-atom entangled states based on cavity quantum electrodynamics technology according to a preferred embodiment of the present invention.

需要说明的是，附图用于说明本发明，而非限制本发明。注意，表示结构的附图可能并非按比例绘制。并且，附图中，相同或者类似的元件标有相同或者类似的标号。It should be noted that the accompanying drawings are used to illustrate the present invention, but not to limit the present invention. Note that drawings showing structures may not be drawn to scale. And, in the drawings, the same or similar elements are marked with the same or similar symbols.

具体实施方式detailed description

为了使本发明的内容更加清楚和易懂，下面结合具体实施例和附图对本发明的内容进行详细描述。In order to make the content of the present invention clearer and easier to understand, the content of the present invention will be described in detail below in conjunction with specific embodiments and accompanying drawings.

本发明基于下述构思：The present invention is based on the following idea:

(1)一位发送者可以选择两位接受者中的任何一位，将被传送量子态传送过去；(1) A sender can choose any one of the two recipients to transmit the quantum state to be transmitted;

(2)两位接收者中的任何一位要重建被传送量子态，都需要另一位接受者的协助，因此可以把另一位接受者看作是控制者；(2) Any one of the two recipients needs the assistance of the other recipient to reconstruct the transmitted quantum state, so the other recipient can be regarded as the controller;

(3)量子信息传输的通道之一是一个三个原子之间的W型纠缠，这使得量子信道能够很好的抵抗环境噪声；(3) One of the channels for quantum information transmission is a W-type entanglement between three atoms, which makes the quantum channel well resistant to environmental noise;

(4)原子的状态代表着信息。利用两能级原子与腔场之间的相互作用，可以实现对原子状态的操控，亦即完成对信息的处理；(4) The state of the atom represents information. Using the interaction between the two-level atoms and the cavity field, the manipulation of the atomic state can be realized, that is, the processing of information can be completed;

(5)本方案利用原子与腔场之间的大失谐相互作用，原子与腔模之间没有能量交换，系统的演化对腔衰减和热场均不敏感。(5) This scheme utilizes the large detuning interaction between atoms and cavity field, there is no energy exchange between atoms and cavity modes, and the evolution of the system is insensitive to cavity attenuation and thermal field.

下面将具体描述本发明的实施例。Embodiments of the present invention will be specifically described below.

相应地，图1示意性地示出了根据本发明优选实施例的基于腔量子电动力学技术的远程制备两原子纠缠态的方法的流程图。其中，根据本发明优选实施例的基于腔量子电动力学技术的远程制备两原子纠缠态的方法基于单个两能级原子与经典电磁场之间的相互作用。Correspondingly, FIG. 1 schematically shows a flowchart of a method for remotely preparing two-atom entangled states based on cavity quantum electrodynamics technology according to a preferred embodiment of the present invention. Among them, the method for remotely preparing two-atom entangled states based on cavity quantum electrodynamics technology according to the preferred embodiment of the present invention is based on the interaction between a single two-level atom and a classical electromagnetic field.

本发明所采用的技术方案中涉及三位空间上分隔开的参与者，一位发送者Alice要帮助两位接收者Bob和Carol中的一位建立起形如下式的两原子纠缠态：The technical solution adopted by the present invention involves three space-separated participants, and a sender, Alice, needs to help one of the two receivers, Bob and Carol, to establish a two-atom entanglement state of the form:

|φ＞＝α|gg＞+β|ee＞|φ＞＝α|gg＞+β|ee＞

其中|g＞和|e＞分别表示两能级原子的基态和激发态，参数α和β为实数，且满足条件α²+β²＝1。发送者Alice掌握着这个量子态的准确信息，但是接收者Bob和Carol对该量子态却是一无所知。为了完成传送信息的任务，Alice在她和两位接收者之间建立起一个两原子纠缠态和一个三原子W类纠缠态作为量子信道Where |g> and |e> represent the ground state and excited state of two-level atoms respectively, the parameters α and β are real numbers, and the condition α ² +β ² =1 is satisfied. The sender Alice has accurate information about this quantum state, but the receivers Bob and Carol know nothing about the quantum state. In order to complete the task of transmitting information, Alice establishes a two-atom entangled state and a three-atom W-like entangled state as quantum channels between her and the two receivers

其中原子1和4属于发送者Alice，原子2和3分别属于接收者Bob和Carol，而原子5交给最终的接收者(Bob或者Carol)。Atoms 1 and 4 belong to the sender Alice, atoms 2 and 3 belong to receivers Bob and Carol respectively, and atom 5 is handed over to the final receiver (Bob or Carol).

为了完成量子态的发送，三位参与者的具体步骤如下：In order to complete the transmission of the quantum state, the specific steps of the three participants are as follows:

第一步骤S1，发送者Alice需要预先制备一个单模腔A，其中腔场的频率与两能级原子的跃迁频率之间的失谐量为δ，原子-腔耦合系数为ε。同时引入一个强经典场驱动原子，经典场的频率与原子跃迁频率相同，经典场的拉比频率为Ω。发送者设置各器件的参数满足条件Ω＞＞δ＞＞ε。随后将原子1和原子4注入单模腔A，发送者根据所拥有的被传送量子态的信息,控制原子飞行时间τ，使其满足条件同时，调节经典场的拉比频率满足条件Ωτ＝π。In the first step S1, the sender Alice needs to prepare a single-mode cavity A in advance, where the mismatch between the frequency of the cavity field and the transition frequency of the two-level atoms is δ, and the atom-cavity coupling coefficient is ε. At the same time, a strong classical field is introduced to drive the atoms, the frequency of the classical field is the same as the atomic transition frequency, and the Rabi frequency of the classical field is Ω. The sender sets the parameters of each device to satisfy the condition Ω>>δ>>ε. Then inject atom 1 and atom 4 into the single-mode cavity A, and the sender controls the flight time τ of the atoms according to the information of the transmitted quantum state, so that it satisfies the condition At the same time, adjusting the Rabi frequency of the classical field satisfies the condition Ωτ=π.

第二步骤S2，完成第一步骤S1后，三个原子所组成的系统的量子态将演化至如下形式：The second step S2, after completing the first step S1, the quantum state of the system composed of three atoms will evolve to the following form:

此时，发送者分别对其所拥有的原子1和原子4进行测量，判断原子处于基态|g＞或激发态|e＞。At this time, the sender measures the atom 1 and atom 4 it owns respectively, and judges that the atom is in the ground state |g> or the excited state |e>.

第三步骤S3，发送者要在两位接收者中选择一位作为最终的接收者，将原子1和原子4的测量结果通过经典信道发送给他/她，并将原子5分配给最终的接收者(Bob/Carol)。In the third step S3, the sender should select one of the two receivers as the final receiver, send the measurement results of atom 1 and atom 4 to him/her through the classical channel, and assign atom 5 to the final receiver The person (Bob/Carol).

第四步骤S4，另一位接收者(Carol/Bob)(即，两位接收者中非最终的接收者的那个接收者)对自己手中的原子(3/2)进行测量，并将测量结果通过经典信道告知最终的接收者(Bob/Carol)。In the fourth step S4, another receiver (Carol/Bob) (that is, the receiver who is not the final receiver among the two receivers) measures the atom (3/2) in his hand, and reports the measurement result The final receiver (Bob/Carol) is notified via a classical channel.

第五步骤S5，最终的接收者(Bob/Carol)根据来自发送者和另一位接收者的经典信息，判断是否完成了远程态制备的任务。In the fifth step S5, the final receiver (Bob/Carol) judges whether the task of remote state preparation is completed according to the classic information from the sender and another receiver.

如果另一位接收者(Carol/Bob)的原子(3/2)处于激发态|e＞，则最终的接收者(Bob/Carol)无法重建被传送量子态。If the atom (3/2) of the other recipient (Carol/Bob) is in the excited state |e>, the final recipient (Bob/Carol) cannot reconstruct the transmitted quantum state.

反之，如果另一位接收者(Carol/Bob)的原子(3/2)处于基态|g＞，则最终的接收者(Bob/Carol)可以通过单原子操作，完成远程态制备的任务。此时，Conversely, if the atom (3/2) of another recipient (Carol/Bob) is in the ground state |g>, then the final recipient (Bob/Carol) can complete the task of remote state preparation through single-atom operations. at this time,

若发送者手中的原子处于|ge＞1，4或|eg＞1，4态，则最终的接收者(Bob/Carol)直接得到了被传送量子态；If the atom in the hands of the sender is in the |ge>1, 4 or |eg>1, 4 state, the final receiver (Bob/Carol) directly obtains the transmitted quantum state;

若发送者的原子处于|gg＞1，4或|ee＞1，4态，则最终的接受者(Bob/Carol)需要利用一个经典场完成一次单原子操作，重建被传送量子态。If the sender's atom is in the |gg>1,4 or |ee>1,4 state, the final receiver (Bob/Carol) needs to use a classical field to complete a single atomic operation to reconstruct the transmitted quantum state.

本发明至少具有如下技术效果：The present invention has at least the following technical effects:

(1)相对于光子系统，原子系统的量子态具有更长的消相干时间，或者说更加的稳定，因而通常被认为是理想的固定比特。这使得其比光子更适合于远程制备过程。因为在远程制备量子态的过程中，作为信息载体的物理系统是不需要传输到其他位置的，而仅需要在本地对其进行操作。因此我们采用了两能级原子作为信息的载体；(1) Compared with the photonic system, the quantum state of the atomic system has a longer decoherence time, or is more stable, so it is usually considered as an ideal fixed bit. This makes them more suitable for remote fabrication processes than photons. Because in the process of remote preparation of quantum states, the physical system as the information carrier does not need to be transmitted to other locations, but only needs to be operated locally. Therefore, we use two-level atoms as the carrier of information;

(2)目前大部分的远程态制备的实验方案中都仅仅考虑了一位发送者和一位接收者的情况，没有考虑到有多位通信参与者的情况。本方案中有三位参与者，一位发送者，一位接收者和一位控制者，其中接收者和控制者两者的地位是等价的，可以由发送者根据具体的情况决定他们最终的任务；(2) Most of the current experimental schemes for remote state preparation only consider the situation of one sender and one receiver, and do not consider the situation of multiple communication participants. There are three participants in this scheme, a sender, a receiver and a controller. The status of the receiver and the controller is equivalent, and the sender can decide their final status according to the specific situation. Task;

(3)本发明的方法采用三原子组成的W型纠缠态作为量子信息传输的信道之一。目前的研究表明，对于三体纠缠态，W型纠缠表现出更高的鲁棒性和更强的非经典特性，从而使其被认为是量子信息处理中理想的纠缠资源。因而，本方法提高了通信过程的抗干扰能力。(3) The method of the present invention adopts the W-type entangled state composed of three atoms as one of the channels for quantum information transmission. The current study shows that for the three-body entangled state, the W-type entanglement exhibits higher robustness and stronger non-classical properties, thus making it considered as an ideal entanglement resource in quantum information processing. Therefore, the method improves the anti-interference ability of the communication process.

由此，本发明提供了一种能够从实际的可操作性出发，提出由一个多方参与的，以两能级原子作为信息的载体，利用两能级原子与经典电磁场之间的相互作用，通过一个三原子W型纠缠态和一个量原子纠缠态组成的量子信息传输信道，完成对两原子量子比特态的远程态制备的方法。Thus, the present invention provides a method that can be started from the actual operability, and a multi-party participation is proposed, with two-level atoms as the carrier of information, using the interaction between the two-level atoms and the classical electromagnetic field, through A quantum information transmission channel composed of a three-atom W-type entangled state and a quantum-atom entangled state completes the remote state preparation method for two-atom qubit states.

此外，需要说明的是，除非特别说明或者指出，否则说明书中的术语“第一”、“第二”、“第三”等描述仅仅用于区分说明书中的各个组件、元素、步骤等，而不是用于表示各个组件、元素、步骤之间的逻辑关系或者顺序关系等。In addition, it should be noted that, unless otherwise specified or pointed out, the terms “first”, “second”, “third” and other descriptions in the specification are only used to distinguish each component, element, step, etc. in the specification, and It is not used to express the logical relationship or sequential relationship between various components, elements, and steps.

可以理解的是，虽然本发明已以较佳实施例披露如上，然而上述实施例并非用以限定本发明。对于任何熟悉本领域的技术人员而言，在不脱离本发明技术方案范围情况下，都可利用上述揭示的技术内容对本发明技术方案作出许多可能的变动和修饰，或修改为等同变化的等效实施例。因此，凡是未脱离本发明技术方案的内容，依据本发明的技术实质对以上实施例所做的任何简单修改、等同变化及修饰，均仍属于本发明技术方案保护的范围内。It can be understood that although the present invention has been disclosed above with preferred embodiments, the above embodiments are not intended to limit the present invention. For any person skilled in the art, without departing from the scope of the technical solution of the present invention, the technical content disclosed above can be used to make many possible changes and modifications to the technical solution of the present invention, or be modified to be equivalent to equivalent changes. Example. Therefore, any simple modifications, equivalent changes and modifications made to the above embodiments according to the technical essence of the present invention, which do not deviate from the technical solution of the present invention, still fall within the protection scope of the technical solution of the present invention.

Claims

1., based on the long-range method preparing two-atom entangled state of Eurytrema coelomatium technology, described method is provided for the foundation that a sender assists in two recipients | Φ >=α | and gg >+β | ee >

The two-atom entangled state of form, wherein | g > and | e > represents ground state and the excitation state of Two level atom respectively, and parameter alpha and β are real number, and the α that satisfies condition ²+ β ²=1; Wherein sender knows the information of this quantum state, and two recipients do not know the information of quantum state; In order to complete the task of transmission information, sender sets up a two-atom entangled state and three atom W class Entangled States as quantum channel between itself and two recipients:

\begin{matrix} | Ψ > = \frac{1}{\sqrt{3}} {(| e g g > + | g e g > + | g g e >)}_{1, 2, 3}, \\ | Ψ > = \frac{1}{\sqrt{2}} {(| g g > + | e e >)}_{4, 5} \end{matrix}

Its Atom 1 and 4 belongs to sender, and atom 2 and 3 belongs to the first recipient and the second recipient respectively, and atom 5 gives final recipient.

2. the long-range method preparing two-atom entangled state based on Eurytrema coelomatium technology according to claim 1, is characterized in that comprising:

First step, sender prepares an one-mode cavity A, and the mismatching angle between the frequency of its lumen field and the jump frequency of Two level atom is δ, and atom-chamber coupling coefficient is ε; And introduce a Strong classical field a driven atom, the frequency of Classical Fields is identical with atomic transition frequency, and the Rabi frequency of Classical Fields is Ω; And, atom 1 and atom 4 are injected one-mode cavity A by the parameter that sender the arranges each device Ω > > δ > > δ that satisfies condition subsequently, sender is transmitted the information of quantum state according to had, control atom flight time τ, make it satisfy condition meanwhile, the Rabi frequency of Classical Fields is regulated to satisfy condition Ω τ=π;

Second step, after completing first step, the quantum state of the system that three atoms form will develop to following form:

\begin{matrix} | Ψ > = \frac{1}{6} [| g g >_{1, 4} {(- i β | g g e > + α | e g g > + α | g e g >)}_{2, 3, 5} \\ + | g e >_{1, 4} {(- i β | g g g > + α | e g e > + α | g e e >)}_{2, 3, 5} \\ + | e g >_{1, 4} {(α | g g g > - i β | e g e > - i β | g e e >)}_{2, 3, 5} \\ + | e e >_{1, 4} {(α | g g e > - i β | e g g > - i β | g e g >)}_{2, 3, 5}] \end{matrix}

Now, sender measures two atoms that it has, and judges that atom is in ground state | g > or excitation state | and e >;

Third step, sender selects one as final recipient in two recipients, the measurement result of atom 1 and atom 4 is sent to final recipient by classical channel, and atom 5 is distributed to final recipient;

4th step, another one recipient measures the atom in oneself hand, and measurement result is informed final recipient by classical channel;

5th step, final recipient, according to the classical information from sender and another one recipient, judges whether to complete task prepared by long-range state.

3. the long-range method preparing two-atom entangled state based on Eurytrema coelomatium technology according to claim 1 and 2, it is characterized in that the 5th step comprises: if the atom of another one recipient is in excitation state | e >, then final recipient can not rebuild by transmission quantum state.

4. the long-range method preparing two-atom entangled state based on Eurytrema coelomatium technology according to claim 1 and 2, it is characterized in that, 5th step comprises: if the atom of another one recipient is in ground state | g >, then final recipient, by monatomic operation, completes task prepared by long-range state.

5. the long-range method preparing two-atom entangled state based on Eurytrema coelomatium technology according to claim 4, is characterized in that, if the atom of sender is in | ge > _{isosorbide-5-Nitrae}or | eg > _{isosorbide-5-Nitrae}state, then final recipient directly obtains being transmitted quantum state;

If the atom of sender is in | gg > _{isosorbide-5-Nitrae}or | ee > _{isosorbide-5-Nitrae}state, then final recipient utilizes Classical Fields to complete once monatomic operation, to rebuild by transmission quantum state.