Showing papers on "No-teleportation theorem published in 2015"
TL;DR: This work uses photon pairs entangled in both degrees of freedom (that is, hyper-entangled) as the quantum channel for teleportation, and develops a method to project and discriminate hyper-ENTangled Bell states by exploiting probabilistic quantum non-demolition measurement, which can be extended to more degrees offreedom.
Abstract: The quantum teleportation of composite quantum states of a single photon encoded in both spin and orbital angular momentum is achieved, with a teleportation fidelity above the classical limit, by quantum non-demolition measurement assisted discrimination of the Bell states describing the entanglement of the two degrees of freedom. In the process known as quantum teleportation, quantum information encoded in a quantum particle, for example a photon, is transferred from one place to the other without ever moving the photon. Although quantum teleportation has been demonstrated with a variety of different systems, all have so far been limited in one crucial aspect: they only allow teleporting one degree of freedom. Here, Nai-Le Liu and colleagues demonstrate quantum teleportation of two degrees of freedom — spin and orbital angular momentum — in a single photon. Their experimental implementation is very complex and entails various innovative techniques, most notably a hybrid Bell-state measurement scheme. The intricacy of this scheme illustrates how difficult it will be to implement quantum teleportation of more complex quantum systems with more degrees of freedom. But this work represents a first and significant step in this direction. Quantum teleportation1 provides a ‘disembodied’ way to transfer quantum states from one object to another at a distant location, assisted by previously shared entangled states and a classical communication channel. As well as being of fundamental interest, teleportation has been recognized as an important element in long-distance quantum communication2, distributed quantum networks3 and measurement-based quantum computation4,5. There have been numerous demonstrations of teleportation in different physical systems such as photons6,7,8, atoms9, ions10,11, electrons12 and superconducting circuits13. All the previous experiments were limited to the teleportation of one degree of freedom only. However, a single quantum particle can naturally possess various degrees of freedom—internal and external—and with coherent coupling among them. A fundamental open challenge is to teleport multiple degrees of freedom simultaneously, which is necessary to describe a quantum particle fully and, therefore, to teleport it intact. Here we demonstrate quantum teleportation of the composite quantum states of a single photon encoded in both spin and orbital angular momentum. We use photon pairs entangled in both degrees of freedom (that is, hyper-entangled) as the quantum channel for teleportation, and develop a method to project and discriminate hyper-entangled Bell states by exploiting probabilistic quantum non-demolition measurement, which can be extended to more degrees of freedom. We verify the teleportation for both spin–orbit product states and hybrid entangled states, and achieve a teleportation fidelity ranging from 0.57 to 0.68, above the classical limit. Our work is a step towards the teleportation of more complex quantum systems, and demonstrates an increase in our technical control of scalable quantum technologies.
608 citations
TL;DR: It is shown that, in the presence of nonlocal memory effects, perfect quantum teleportation can be achieved even with mixed photon polarisation states, which implies that memory effects can be exploited in harnessing noisy quantum systems for quantum communication and that non-Markovianity is a resource for quantum information tasks.
Abstract: One of the most striking consequences of quantum physics is quantum teleportation – the possibility to transfer quantum states over arbitrary distances. Since its theoretical introduction, teleportation has been demonstrated experimentally up to the distance of 143 km. In the original proposal two parties share a maximally entangled quantum state acting as a resource for the teleportation task. If, however, the state is influenced by decoherence, perfect teleportation can no longer be accomplished. Therefore, one of the current major challenges in accomplishing teleportation over long distances is to overcome the limitations imposed by decoherence and the subsequent mixedness of the resource state. Here we show that, in the presence of nonlocal memory effects, perfect quantum teleportation can be achieved even with mixed photon polarisation states. Our results imply that memory effects can be exploited in harnessing noisy quantum systems for quantum communication and that non-Markovianity is a resource for quantum information tasks.
110 citations
TL;DR: In this paper, a bidirectional quantum controlled teleportation scheme by using a genuine six-qubit entangled state is proposed, where Alice may transmit an arbitrary single qubit state of qubit A to Bob and Bob may transmit another qubit to Alice via the control of the supervisor Charlie.
Abstract: A bidirectional quantum controlled teleportation scheme by using a genuine six-qubit entangled state is proposed. In our scheme, such a six-qubit entangled state is employed as the quantum channel linking three legitimate participants. And Alice may transmit an arbitrary single qubit state of qubit A to Bob and Bob may transmit an arbitrary single qubit state of qubit B to Alice via the control of the supervisor Charlie. This bidirectional quantum controlled teleportation is deterministic.
89 citations
TL;DR: In this article, the authors proposed a new protocol of bidirectional and asymmetric quantum controlled teleportation, using a maximally seven-qubit entangled state as the quantum channel, where Alice wants to transmit an arbitrary single qubit state to Bob and Bob wants to send an arbitrary two qubit states to Alice via the control of the supervisor Charlie.
Abstract: We propose a new protocol of bidirectional and asymmetric quantum controlled teleportation, using a maximally seven-qubit entangled state as the quantum channel. That is to say Alice wants to transmit an arbitrary single qubit state (an arbitrary two-qubit state) to Bob and Bob wants to transmit an arbitrary two-qubit state (an arbitrary single state) to Alice via the control of the supervisor Charlie.
59 citations
TL;DR: This work considers a task between two players, Alice and Bob, where quantum resources are infinitely more powerful than their classical counterpart, and a version of the task where the parties may have access to entanglement.
Abstract: Quantum resources can be more powerful than classical resources-a quantum computer can solve certain problems exponentially faster than a classical computer, and computing a function of two parties' inputs can be done with exponentially less communication with quantum messages than with classical ones. Here we consider a task between two players, Alice and Bob where quantum resources are infinitely more powerful than their classical counterpart. Alice is given a string of length n, and Bob's task is to exclude certain combinations of bits that Alice might have. If Alice must send classical messages, then she must reveal nearly n bits of information to Bob, but if she is allowed to send quantum bits, the amount of information she must reveal goes to zero with increasing n. Next, we consider a version of the task where the parties may have access to entanglement. With this assistance, Alice only needs to send a constant number of bits, while without entanglement, the number of bits Alice must send grows linearly with n. The task is related to the Pusey-Barrett-Rudolph theorem which arises in the context of the foundations of quantum theory.
39 citations
TL;DR: In this article, a photonic hybrid remote state preparation from spin to orbital angular momentum degrees of freedom is presented, where the state to be transferred is completely unknown to the sender, whereas in state preparation it should be known to the receiver.
Abstract: There exists two prominent methods to transfer information between two spatially separated parties, namely Alice (A) and Bob (B): quantum teleportation and remote state preparation. However, the difference between these methods is, in the teleportation scheme, the state to be transferred is completely unknown, whereas in state preparation it should be known to the sender. In addition, photonic state teleportation is probabilistic due to the impossibility of performing a two-particle complete Bell-state analysis with linear optics, while remote state preparation can be performed deterministically. Here we report the first realization of photonic hybrid remote state preparation from spin to orbital angular momentum degrees of freedom. In our scheme, the polarization state of photon A is transferred to orbital angular momentum of photon B. The prepared states are visualized in real time by means of an intensified CCD camera. The quality of the prepared states is verified by performing quantum state tomography, which confirms an average fidelity higher than 99.4%. We believe that this experiment paves the way towards a novel means of quantum communication in which encryption and decryption are carried out in naturally different Hilbert spaces, and therefore may provide a means for enhancing security.
33 citations
TL;DR: An experimental realization of non-local classical optical correlation from the Bell's measurement used in tests of quantum non-locality is reported, giving novel insight into quantum physics and may open a new field of applications in quantum information.
Abstract: This study reports an experimental realization of non-local classical optical correlation from the Bell's measurement used in tests of quantum non-locality. Based on such a classical Einstein–Podolsky–Rosen optical correlation, a classical analogy has been implemented to the true meaning of quantum teleportation. In the experimental teleportation protocol, the initial teleported information can be unknown to anyone and the information transfer can happen over arbitrary distances. The obtained results give novel insight into quantum physics and may open a new field of applications in quantum information.
30 citations
TL;DR: In this paper, the authors demonstrate the operation of a quantum relay over 1 km of optical fiber, which teleports a sequence of photonic quantum bits to a receiver by utilizing entangled photons emitted by a semiconductor LED.
Abstract: Quantum cryptography allows confidential information to be communicated between two parties, with secrecy guaranteed by the laws of nature alone. However, upholding guaranteed secrecy over quantum communication networks poses a further challenge, as classical receive-and-resend routing nodes can only be used conditional of trust by the communicating parties. Here, we demonstrate the operation of a quantum relay over 1 km of optical fiber, which teleports a sequence of photonic quantum bits to a receiver by utilizing entangled photons emitted by a semiconductor LED. The average relay fidelity of the link is 0.90+/-0.03, exceeding the classical bound of 0.75 for the set of states used, and sufficiently high to allow error correction. The fundamentally low multi-photon emission statistics and the integration potential of the source present an appealing platform for future quantum networks.
29 citations
TL;DR: In this paper, the authors translate the quantum teleportation protocol into a sequence of coherent operations involving three degrees of freedom of a classical laser beam, which they demonstrate experimentally, and illustrate the possibility of new optical applications based on this intriguing classical analogue of quantum entanglement.
Abstract: We translate the quantum teleportation protocol into a sequence of coherent operations involving three degrees of freedom of a classical laser beam. The protocol, which we demonstrate experimentally, transfers the polarisation state of the input beam to the transverse mode of the output beam. The role of quantum entanglement is played by a non-separable mode describing the path and transverse degrees of freedom. Our protocol illustrates the possibility of new optical applications based on this intriguing classical analogue of quantum entanglement.
27 citations
TL;DR: The deterministic quantum information splitting of arbitrary two-qubit state in cavity quantum electrodynamics is implemented and found to be secure in all these cases.
Abstract: In this paper, we proposed a scheme for quantum information splitting of arbitrary two-qubit by using four-qubit cluster state and Bell-state as quantum channel. The splitter (Alice) and two receivers (Bob and Charlie) safely share a four-qubit cluster and Bell-state as quantum channel. Then, the sender Alice first performs Bell-state measurement (BSMs) on her qubit pairs, respectively, and tells the results to the receiver Bob and Charlie via a classical channel. But it is impossible for Bob to reconstruct the original state with local operations without help from Charlie. If Charlie allows Bob to reconstruct the original state information, he also needs to perform BSMs on his qubits and tell Bob the measurement result. Using the measurement results from Alice and Charlie, Bob can reconstruct the original state by applying the appropriate unitary operation. The scheme is tested against various attack scenarios such as eavesdropping attack, eavesdropping in the presence of a malicious attacker and even in the presence of a dishonest agent and found to be secure in all these cases. In addition, the deterministic quantum information splitting of arbitrary two-qubit state in cavity quantum electrodynamics is implemented.
21 citations
TL;DR: In this article, a seven-qubit entangled state can be used to realize the deterministic quantum state sharing (QSTS) of an arbitrary threequbit state by performing only the Bell state measurements and single qubit measurement.
Abstract: In this paper, we demonstrate that a seven-qubit entangled state can be used to realize the deterministic quantum state sharing (QSTS) of an arbitrary three-qubit state by performing only the Bell-state measurements and single-qubit measurement.
TL;DR: An optimization procedure which can be used to minimize the classical communication cost in preparing a general pure qubit is proposed, linked to the uniform arrangement of $$N$$N points on the Bloch sphere, which provides a geometric description.
Abstract: How to use shared entanglement and forward classical communication to remotely prepare an arbitrary (mixed or pure) state has been fascinating quantum information scientists. Berry has given a constructive scheme for remotely preparing a general pure state, using a pure entangled state and finite classical communication. To optimize the classical communication cost, Berry employed a coding of the high-dimensional target state. Though working in the high-dimensional cases, the coding method is inapplicable for low-dimensional systems, such as a pure qubit. Since qubit plays a central role in quantum information theory, here we propose an optimization procedure which can be used to minimize the classical communication cost in preparing a general pure qubit. Interestingly, our optimization procedure is linked to the uniform arrangement of $$N$$N points on the Bloch sphere, which provides a geometric description.
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TL;DR: In this article, a novel protocol for bidirectional controlled quantum teleportation (BCQT) is proposed based on entanglement swapping of initiate Bell state, two users can teleport an unknown single-qubit state to each other under the permission of the supervisor.
Abstract: In this paper, a novel protocol for bidirectional controlled quantum teleportation (BCQT) is proposed. Based on entanglement swapping of initiate Bell state, two users can teleport an unknown single-qubit state to each other under the permission of the supervisor. This proposed protocol would be utilized to a system in which a controller controls the communication in one direction only. Indeed, just one of the users needs the permission of the controller to reconstruct the unknown quantum state. In comparison to the existing BCQT protocols which their quantum channels are cluster and brown state, the proposed protocol is more practical within todays technology, since it merely uses Bell states as the quantum resource.
TL;DR: In this article, the authors proposed a scheme of quantum information splitting arbitrary three-qubit state by using seven qubits entangled as quantum channel. But the scheme is not suitable for the case where the sender Alice and the receiver Charlie performed Bell-state measurements on their qubits pairs respectively.
Abstract: In this paper, we propose a scheme of quantum information splitting arbitrary three-qubit state by using seven-qubit entangled as quantum channel. The sender Alice first performs Bell-state measurements (BSMs) on her qubits pairs respectively and tells her measurement outcome to authorizers Bob to reconstruct the original state, then Charlie should carries out single-qubit measurement (SQM) on his qubits. According to the results from Alice and Charlie, Bob can reconstruct the original state by applying an appropriate unitary operation. After analyzing, the method achieved the desired effect of quantum information splitting (QIS). We also realize the QIS of arbitrary three-qubit state in cavity quantum electrodynamics (QED).
TL;DR: A two-step quantum dialogue scheme is put forward with a class of three-qubit W state and quantum dense coding, which utilizes the entangle properties of Wstate and decoy photon checking technique to realize three-time channel detection.
Abstract: A two-step quantum dialogue scheme is put forward with a class of three-qubit W state and quantum dense coding. Each W state can carry three bits of secret information and the measurement result is encrypted without information leakage. Furthermore, we utilize the entangle properties of W state and decoy photon checking technique to realize three-time channel detection, which can improve the efficiency and security of the scheme.
TL;DR: This work defines an analogue of a random access code, where instead of classical bits, one encodes qubits, and provides a quantum non-signaling box that if supported with two classical bits allows to simulate a quantum version ofrandom access code.
Abstract: A well-known cryptographic primitive is the so-called random access code. Namely, Alice is to send to Bob one of two bits, so that Bob has the choice of which bit he wants to learn about. However, at any time, Alice should not learn Bob's choice, and Bob should learn only the bit of his choice. The task is impossible to accomplish by means of either classical or quantum communication. On the other hand, a concept of correlations stronger than quantum ones, exhibited by the so-called Popescu-Rohrlich box, was introduced and widely studied. In particular, it is known that the Popescu-Rohrlich box enables simulation of the random access code with the support of one bit of communication. Here, we propose a quantum analog of this phenomenon. Namely, we define an analog of a random access code, where instead of classical bits, one encodes qubits. We provide a quantum nonsignaling box that if supported with two classical bits, allows one to simulate a quantum version of a random access code. We point out that two bits are necessary. We also show that a quantum random access code cannot be fully quantum: when Bob inputs the superposition of two choices, the output will be in a mixed state rather than in a superposition of required states.
TL;DR: Two novel schemes are proposed to teleport an unknown two-level quantum state probabilistically when the sender and the receiver only have partial information about the quantum channel, respectively.
Abstract: Two novel schemes are proposed to teleport an unknown two-level quantum state probabilistically when the sender and the receiver only have partial information about the quantum channel, respectively. This is distinct from the fact that either the sender or the receiver has entire information about the quantum channel in previous schemes for probabilistic teleportation. Theoretical analysis proves that these schemes are straightforward, efficient and cost-saving. The concrete realization procedures of our schemes are presented in detail, and the result shows that our proposals could extend the application range of probabilistic teleportation.
TL;DR: In this article, a scheme of probabilistic teleportation was proposed, in which a six-qubit nonmaximally cluster state was used as the quantum channel to teleport an unknown three-qubits entangled state.
Abstract: A scheme of probabilistic teleportation was proposed. In this scheme, we took a six-qubit nonmaximally cluster state as the quantum channel to teleport an unknown three-qubit entangled state. Based on Bob’s three times Bell state measurement (BSM) results, the receiver Bob can by introducing an auxiliary particle and the appropriate transformation to reconstruct the initial state with a certain probability. We found that, the successful transmission probability depend on the absolute value of coefficients of two of six particle cluster state minimum.
TL;DR: In this paper, the authors proposed a simple and useful scheme to realize the teleportation of a two-qubit entangled state with the help of four qubit cluster state in trapped ions which involves the interaction of two ions.
Abstract: In this paper, we propose a simple and useful scheme to realize the teleportation of a two-qubit entangled state with the help of four-qubit cluster state in trapped ions which involves the interaction of two ions. Our scheme uses a cluster state as the quantum channel, where we do not need any Bell-state measurement. Thus it is insensitive to the thermal motion, which is of importance in view of experiment. Meanwhile, the successful probability can both reach 1.0.
TL;DR: In this paper, a new application of the GHZ-like state is investigated for teleportation of an arbitrary three-qubit state, where three sets of GHZlike states can be used to realize the perfect teleportation.
Abstract: A new application of the GHZ-like state is investigated for teleportation of an arbitrary three-qubit state. We demonstrate that three sets of GHZ-like states can be used to realize the perfect teleportation of an arbitrary three-qubit state by performing only the three-qubit von-Neumann projective measurements.
Patent•
19 Feb 2015
TL;DR: In this article, the authors proposed a method for interaction-free entanglement of quantum bits in quantum computers, in which the quantum bits to be entangled are available in the state Ψ 44 with arbitrarily real phases φ and θ as an elementary quantum system.
Abstract: A method for interaction-free entanglement of quantum bits in quantum computers, in which the quantum bits to be entangled are available in the state Ψ 44 with arbitrarily real phases φ and θ as an elementary quantum system. The two quantum bits ( 1 ) and ( 2 ) are localized in spatial regions ( 6 ) and ( 6 ′) and surrounded by switchable sheaths ( 7 ) and ( 7 ′) preferably a superconductor with the jump temperature T SU . The switchable sheaths, in the activated state, completely displace a global, homogeneous magnetic field B z from the spatial regions ( 6 ) and ( 6 ′). In the inactivated state, the switchable sheaths do not shield the spatial regions ( 6 ) and ( 6 ′). If the switchable sheaths are switched from the activated state into the inactivated state while observing the boundary condition (R 3 ), as a result of this, the two quantum bits ( 1 ) and ( 2 ) are transferred into the entangled state Ψ − .
TL;DR: This work proposes the first multi-controller quantum teleportation with remote rotations, which allows a sender to teleport an arbitrary qubit to a receiver and at the same time, many controllers can remotely perform two kinds of rotation operations with various angles on the teleported qubit.
Abstract: This work proposes the first multi-controller quantum teleportation with remote rotations, which allows a sender to teleport an arbitrary qubit to a receiver and at the same time, many controllers can remotely perform two kinds of rotation operations with various angles on the teleported qubit. In order to show its usefulness, a controlled quantum teleportation protocol has also been proposed.
TL;DR: A novel three-particle partially entangled state which is suitable for perfect controlled teleportation is constructed and detailed calculations and simulation analyses show that the constructed state is a suitable channel for controlled teleportation of arbitrary qubits, unit teleportation fidelity and 100% success probability.
TL;DR: The quantum information introduced by quantum mechanics is equivalent to that generalization of the classical information from finite to infinite series or collections as discussed by the authors, which is the quantity of choices measured in the units of elementary choice.
Abstract: The quantum information introduced by quantum mechanics is equivalent to that generalization of the classical information from finite to infinite series or collections. The quantity of information is the quantity of choices measured in the units of elementary choice. The qubit can be interpreted as that generalization of bit, which is a choice among a continuum of alternatives. The axiom of choice is necessary for quantum information. The coherent state is transformed into a well-ordered series of results in time after measurement. The quantity of quantum information is the ordinal corresponding to the infinity series in question
TL;DR: This paper looks at using quantum teleportation for secure message exchange by directly teleporting message bits instead of encryption keys and is the first protocol of it’s type where the role of the sender and receiver are flipped around.
Abstract: This paper looks at using quantum teleportation for secure message exchange. Although the proposed protocol has parallels with Ekert’s protocol for key distribution, we look at the issue of directly teleporting message bits instead of encryption keys. Further, it is the first protocol of it’s type where the role of the sender and receiver are flipped around. In other words, unlike traditional protocols, in the proposed protocol the receiver first performs certain measurements thus implicitly determining a stream of bits that she combines with the bit stream received from the sender to determine the secret message. There are no qubits wasted in random measurements.
TL;DR: In this paper, a new quantity known as the particle filter was introduced, which acts like a catalyst via the use of transverse and longitudinal relaxations to speed up teleportation of single qubit state from the sender to the intermediary and then to the receiver.
Abstract: Quantum teleportation is at its advanced research stage and has attracted more novel discoveries in recent time. The Bloch NMR was used to highlight the specification for the construction of a virtual Magnetic-Not (M-Not) gate to analyze a two trans-sectional multiple arbitrary states. A new version of quantum manipulation for entanglement and disentanglement of particles was introduced. A new quantity known as the particle filter was discovered. The particle-filter acts like a catalyst via the use of transverse and longitudinal relaxations to speed-up teleportation of single qubit state from the sender to the intermediary and then to the receiver. The efficiency of the M-Not gates to filter both noise and excited qubit state during teleportation was shown. DOI: http://dx.doi.org/10.11591/telkomnika.v13i1.6437
01 Dec 2015
TL;DR: The upper bound on the total number of classical communication which is required to achieve quantum communication is provided by means of local phase deviation correction of the encoding procedure of nonlinear coding scheme.
Abstract: Considering the problem of how to efficiently transmit unknown quantum states in multi-unicast networks, we propose a nonlinear quantum network coding scheme with classical communication resource. On the conditions of free classical communication between adjacent nodes in a network, as well as unlimited capacities of classical channels, perfect quantum network coding is available. By means of local phase deviation correction, we design the encoding procedure of nonlinear coding scheme. Moreover, we provide the upper bound on the total number of classical communication which is required to achieve quantum communication, as well as the analysis of scheme property.
TL;DR: In this paper, the authors proposed a scheme for splitting a three-qubit GHZ state by using the maximally entangled state as the quantum channel, where the state receiver can reconstruct the original state of the sender by applying the appropriate unitary operation.
Abstract: In this article, we propose a scheme for splitting a three-qubit GHZ state by using the maximally entangled state as the quantum channel. It will be shown that the state receiver can reconstruct the original state of the sender by applying the appropriate unitary operation. The scheme needs some additional classical information and not Bell-basis measurements. Furthermore, this protocol is feasible with the present technique.
01 Jan 2015
TL;DR: The purpose of this chapter is to provide an overview of Quantum Information theory starting from Classical Information Theory, with the aim to define information mathematically and quantitatively, represent the information in an efficient way for storage and transmission, and ensure the protection of information in the presence of noise and other impairments.
Abstract: The purpose of this chapter is to provide an overview of Quantum Information theory starting from Classical Information Theory, with the aim to: (1) define information mathematically and quantitatively, (2) represent the information in an efficient way (through data compression) for storage and transmission, and (3) ensure the protection of information (through encoding) in the presence of noise and other impairments. In Classical Information theory, the above goals are accomplished in accordance to the laws of Classical Physics. In Quantum Information theory, they are based on quantum mechanical principles and are intrinsically richer than in their Classical counterpart, because of intriguing resources, as entanglement; also, they are more interesting and challenging.
29 Oct 2015
TL;DR: This work derives the maximum coherent information of this virtual quantum channel under noisy classical channel existing between the end users by treating teleportation as a transfer of qubits between end users sharing avirtual quantum channel.
Abstract: Teleportation is a well known protocol to transfer one qubit between users sharing a Bell pair. By treating teleportation as a transfer of qubits between end users sharing a virtual quantum channel, we derive the maximum coherent information of this virtual quantum channel under noisy classical channel existing between the end users. We also study various communication scenarios using hyper entangled states and quantify the advantages over a single degree of freedom.