Symmetric bidirectional quantum teleportation using a six-qubit cluster state as a quantum channel

Abstract

Bidirectional quantum teleportation is a fundamental protocol for exchanging quantum information between two quantum nodes. Till now, all bidirectional quantum teleportation protocols have achieved a maximum efficiency of $$40\%$$ . Here, we propose a new scheme for a symmetric bidirectional quantum teleportation using a six-qubit cluster state as the quantum channel, for symmetric ( $$3\leftrightarrow 3$$ ) qubit bidirectional quantum teleportation of a special three-qubit entangled state. The novelty of our scheme lies in its generalisation for ( $$N\leftrightarrow N$$ ) qubit bidirectional quantum teleportation employing a 2N-qubit cluster state. The efficiency of the proposed protocol is remarkably increased to $$50\%$$ which is the highest till now. Interestingly, only GHZ-state measurements and four Toffoli-gate operations are necessary which is independent of the number (N) of qubits to be teleported.