Multi-parties Controlled Dense Coding via Maximal Slice States and the Physical Realization Using the Optical Elements

An efficient scheme for controlled dense coding is presented with the aid of the introduction of auxiliary particles, appropriate local unitary operations and measurement basis. In this proposal, the four-qubits maximal slice state, which belongs to partially entangled states, is used as quantum channel. The concrete implementation procedures for our scheme with one sender, one receiver and two controllers are given in detail, and the average transmitted classical information from the sender to the receiver is calculated. Additionally, the physical realization of this proposal is discussed based on the optical elements.     

Deterministic Controlled Remote State Preparation of Real-Parameter Multi-Qubit States via Maximal Slice States

By exploiting three-qubit entangled states and appropriate measurement basis, we propose efficient protocols for deterministic controlled remote state preparation of arbitrary real-parameter multi-qubit states, in which the maximal slice states are used as quantum channel. The successful probability of our schemes can reach up to 100% by using multi-qubit mutually orthogonal measurement basis without the introduction of auxiliary particles. Based on the implementation schemes for preparing arbitrary two- and three-qubit states with real parameters, we have derived the controlled remote state preparation protocols for arbitrary real-parameter multi-qubit states.

     

Probabilistic Dense Coding Using Non-Maximally Entangled Three-Particle States

We present a scheme for probabilistic dense coding via quantum channels of non-maximally entangled threeparticle states. Quantum dense coding will succeed with a certain probability if the sender introduces an auxiliary particle and performs a collective unitary transformation. The average information transmitted in this scheme is calculated.     

Permutation Matrix Method for Dense Coding Using GHZ States

We present a new method called the permutation matrix method to perform dense coding using Greenberger--Horne--Zeilinger (GHZ) states. We show that this method makes the study of dense coding systematically and regularly. It also has high potential to be realized physically.     

Controlled Dense Coding via Partially Entangled States and its Quantum Circuits

In this paper, an efficient scheme for controlled dense coding is presented via partially entangled states with the aid of auxiliary particles and appropriate local unitary operations. The detail implementation producers for our proposal are given, and the total average amount of classical information, which is depending on the superposition factors of quantum channel and measurement basis of the controller, is calculated. Moreover, it is demonstrated that this proposal can be realizable based on quantum circuits.     

Controlled Dense Coding between Multi-Parties

Controlled dense coding via multi-particles GHZ state and multi-particles GHZ-class state are exploited in this letter. The quantum channel and the amount of information between the senders and the receivers are controlled by the supervisor via his local measurement. The amount of information is determined by Charlie’s measurement in the former case of GHZ state, and also by the coefficients of the original GHZ-class state in the latter case.     

Controlled Dense Coding by Using GHZ-Type State in Cavity QED

We present an experimentally feasible protocol for implementing controlled dense coding by using a three-atom GHZ-type state in cavity quantum electrodynamics (QED). In cavity QED system, we have proposed to generate a three-atom GHZ-type state and demonstrated that the probability of implementing controlled dense coding is 100 %. In addition, our approach can be realized with present cavity QED techniques.     

Controlled Dense Coding with Symmetric State

Two schemes, introducing the projective operator and the auxiliary qubit respectively, for controlled dense coding are investigated by using a three-qubit symmetric state with entanglement, where the supervisor (Cliff) can control an average amount of information transmitted from the sender (Alice) to the receiver (Bob) by adjusting the measurement angle θ. We show that the results for the average amounts of information are unique from the different two schemes. The schemes may be extended to many-qubit systems.     

Controlled Simultaneous Teleportation and Dense Coding

We propose a teleportation protocol and a dense coding protocol. In these protocols, one sender intends to send quantum states or classical bits to two receivers through two GHZ entanglement channels. The entanglement channels are locked by the sender and the communication process is supervised by a controller. In order to obtain the messages, the receivers need the controller’s permission, and must collaborate to unlock the entanglement channels.     

Controlled Dense Coding with Six-Qubit Cluster State

Two schemes, via generalized measurement and with entanglement concentration respectively, for controlled dense coding with a six-qubit cluster state are investigated in detail. In these protocols, the supervisor (Cliff) can control the average amount of information transmitted from the senders (Alice and David) to the receiver (Bob) by adjusting the local measurement angle θ. It is shown that the results for the average amounts of information are unique from the different two schemes.     

Controlled Dense Coding with Four-Qubit Entangled State

Two schemes, via generalized measurement and with entanglement concentration respectively, for controlled dense coding with a four-qubit entangled state are investigated in detail. In the two schemes, the supervisor (Cliff) can control the average amount of information transmitted from the sender (Alice) to the receiver (Bob) by adjusting the local measurement angle θ. It is shown that the results for the average amounts of information are unique from the different two schemes.     

Controlled Dense Coding with Four-Particle Entangled State

Two schemes, via generalized measurement and entanglement concentration respectively, for dense coding are investigated by using a four-particle entangled state, in which the supervisor can control the average amount of information transmitted from the sender to the receiver by adjusting the local measurement angle. It is shown that the results for the average amounts of information are unique from the different two schemes.     

Controlled Dense Coding using Generalized GHZ-type State

Two schemes for controlled dense coding with a extended GHZ-type state are investigated. In this protocol, the supervisor (Cliff) can control the channel and the average amount of information transmitted from the sender (Alice) to the receiver (Bob) by adjusting the local measurement angle θ. It is shown that the results for the average amounts of information are unique from the different two schemes.     

Controlled Dense Coding with Five-Qubit Cluster State

Two schemes, via entanglement concentration and with generalized measurement respectively, for controlled dense coding with a one-dimensional five-qubit cluster state are investigated. In this protocol, the supervisor (Cliff) can control the entanglement of the channel and the average amount of information transmitted from the sender (Alice) to the receiver (Bob) by adjusting the local measurement angle θ. It is shown that the results for the average amounts of information are unique from the different two schemes.     

Scheme for Controlled Dense Coding via Cavity Decay

A scheme for controlled dense coding via cavity decay is proposed. In the scheme, two degenerate ground states of six-level atoms are used as the storage qubits and the leaky photons act as flying qubits. The system is robust against atomic spontaneous emissions and decoherence of cavity field. And the successful probability is nearly 1 with quantum nondemolition parity detectors and photon detectors. The scheme may be realized based on current technologies.     

Scheme for Controlled Dense Coding via Cavity Decay

A scheme for controlled dense coding via cavity decay is proposed. In the scheme, two degenerate ground states of six-level atoms are used as the storage qubits and the leaky photons act as flying qubits. The system is robust against atomic spontaneous emissions and decoherence of cavity field. And the successful probability is nearly 1 with quantum nondemolition parity detectors and photon detectors, The scheme may be realized based on current technologies.     

Controlled Dense Coding with a Four-Particle Non-maximally Entangled State

Two schemes for controlled dense coding with a four-particle entangled state are investigated, one with entanglement concentration and the other with generalized measurement. In these protocols, the supervisor (Cliff) can control the average amount of information transmitted from the sender (Alice and David) to the receiver (Bob) only by adjusting his local measurement angle θ. It is shown that the results for the average amounts of information are unique from the different two schemes.     

Controlled Dense Coding Through a Genuine Five-Atom Entangled State in Cavity QED

We present an experimentally feasible scheme for implementing controlled dense coding through a genuine five-atom entangled state in cavity QED. The scheme is insensitive to both the cavity decay and the thermal field. In the scheme that four-atom entangled states can be exactly distinguished with detecting the atomic state, and the controlled dense coding can be realized in a simple way.