Quantum teleportation allows one to transmit an arbitrary qubit from point A to point B using a pair of (pre-shared) entangled qubits and classical bits of information. The conventional protocol for teleportation uses two bits of classical information and assumes that the sender has access to only one copy of the arbitrary qubit to be sent. Here, we ask whether we can do better than two bits of classical information if the sender has access to multiple copies of the qubit to be teleported. We place no restrictions on the qubit states. Consequently, we propose a modified quantum teleportation protocol that allows Alice to reset the state of the entangled pair to its initial state using only local operations. As a result, the proposed teleportation protocol requires the transmission of only one classical bit with a probability greater than one-half. This has implications for efficient quantum communications and the security of quantum cryptographic protocols based on quantum entanglement.
Quantum teleportation allows one to transmit an arbitrary qubit from point A to point B using a pair of (pre-shared) entangled qubits and classical bits of information. The conventional protocol for teleportation uses two bits of classical information and assumes that the sender has access to only one copy of the arbitrary qubit to be sent. Here, we ask whether we can do better than two bits of classical information if the sender has access to multiple copies of the qubit to be teleported. We place no restrictions on the qubit states. Consequently, we propose a modified quantum teleportation protocol that allows Alice to reset the state of the entangled pair to its initial state using only local operations. As a result, the proposed teleportation protocol requires the transmission of only one classical bit with a probability greater than one-half. This has implications for efficient quantum communications and the security of quantum cryptographic protocols based on quantum entanglement.
We proposed an N-qubit GHZ-like state quantum teleportation protocol using a two-qubit entangled quantum channel state assisted with only one classical bit. In this protocol, we use CNOT gates and a reset procedure, assuming the sender has many copies of the state that will be teleported. The CNOT gates can reduce the number of N-qubit to only one qubit, while the reset procedure may reduce the number of classical bits required to only one classical bit. Lastly, we show that the teleportation success probability depends on the state of the N-qubit state’s coefficients and is generally more than one-half.
Quantum teleportation provides a “bodiless” way of transmitting the quantum state from one object to another, at a distant location, using a classical communication channel and a previously shared entangled state. In this paper, we present a tripartite scheme for probabilistic teleportation of an arbitrary single qubit state, without losing the information of the state being teleported, via a fourqubit cluster state of the form | ϕ > 1234 = α |0000>+ β |1010>+ γ |0101>- η |1111>, as the quantum channel, where the nonzero real numbers α , β , γ , and η satisfy the relation j α j2 + | β | 2 + | γ | 2 + | η | 2 = 1. With the introduction of an auxiliary qubit with state |0>, using a suitable unitary transformation and a positive-operator valued measure (POVM), the receiver can recreate the state of the original qubit. An important advantage of the teleportation scheme demonstrated here is that, if the teleportation fails, it can be repeated without teleporting copies of the unknown quantum state, if the concerned parties share another pair of entangled qubit. We also present a protocol for quantum information splitting of an arbitrary two-particle system via the aforementioned cluster state and a Bell-state as the quantum channel. Problems related to security attacks were examined for both the cases and it was found that this protocol is secure. This protocol is highly efficient and easy to implement.
Abstract In this study, we propose an encrypted quantum teleportation broadcast scheme using a 6-qubit entangled channel and an encrypted quantum teleportation scheme with a controller via a 7-qubit entangled channel. The quantum state of Alice, to be transmitted, is first encrypted into two distinct states that satisfy certain conditions. As the main sender, Alice designates two agents to transmit encrypted states to two receivers. She shares a 6-qubit entangled state with each party and provides the receivers with a 1-bit classical information containing the chosen encryption. After the agents perform measurements on the corresponding orthogonal bases and send the results to the receivers, each receiver can reconstruct the original state sent by Alice. To enhance security for the receivers, the scheme introduces Alice as a controller. The receivers can reconstruct the original state only if Alice performs a measurement and shares her measurement outcome. The use of encryption ensures that even if an agent’s qubit is intercepted, the actual state remains secure. Alice, as the controller, can also terminate the transmission if a security threat is detected or she change her mind to finish the transmission. The teleportation performance depends on how the qubit is encrypted. For a specific input state used as an example, the protocol obtained a teleportation success probability of 0.9608.
In this work, we consider two stages one qubit quantum teleportation protocol via an arbitrary entangled two qubits state. In the first stage, Alice use XOR gate and computational basis measurement, while for the second stage, Alice use Hadamard gate and another computational basis measurement. Alice sent measurement result to Bob via one classical bit each. As the result, we show that this teleportation can has unit fidelity if the channel used has non-zero two terms and maximally entangled. Then the protocol is applicable if the channel is one of four Bell's state.
Abstract This study re-evaluates Parakh’s one-classical-bit quantum teleportation protocol, in which the proposed protocol replaces the traditional two-classical-bit requirement with a reset procedure, resulting in only one classical bit. However, if the input (to-be-teleported) state is unknown, the reset procedure cannot always work effectively, thereby limiting the protocol’s performance. This study modifies the protocol by adding simple CNOT operations, which ensures that the reset procedure always works properly even when the input state is unknown. We also compute the upper bound of the teleportation success probability and the classical bit resource cost inequality using the one-classical-bit protocol. Finally, we simulate the protocol in Qiskit and discuss the results.
FINDING: Quantum teleportation transfers quantum *state* (information), not matter — no particle traverses the channel; only a classical 2-bit message plus a pre-shared entangled pair is required. | MATH: Protocol (Bennett et al. 1993): Alice holds unknown state |ψ⟩ = α|0⟩ + β|1⟩ (|α|²+|β|²=1) and one qubit of a Bell pair |Φ⁺⟩ = (|00⟩+|11⟩)/√2. Joint Bell-basis measurement yields one of 4 outcomes {|Φ±⟩,|Ψ±⟩}, each probability 1/4. Alice sends 2 classical bits (log₂4 = 2). Bob applies one of {I, X, Z, XZ} to recover |ψ⟩ exactly. Fidelity F=1; no-cloning preserved (state destroyed at Alice). | CONNECTION: The 4 Bell states form an orthonormal basis of the 2-qubit Hilbert space ℂ²⊗ℂ² ≅ ℂ⁴ — a complete measurement basis. The 1/4 uniform outcome probability is the maximally-mixed (maximally-entangled) reference state ρ = I/4. This is the qubit analogue of a 4-fold symmetric point group (C₂ᵥ-like), and the Pauli group {I,X,Y,Z} is the order-4 operator set closing under multiplication. The √ Author: Andrew Stewart Caldin, Independent Researcher, UK. Part of the E8 Intelligence Research series. Platform: e8intelligence.com