Quantum teleportation of spin coherent states: beyond continuous variables teleportation

Alexey N Pyrkov,Tim Byrnes

doi:10.1088/1367-2630/16/7/073038

Abstract

We introduce a quantum teleportation scheme that transfers a spin coherent state between two locations using entanglement. In the scheme an unknown spin coherent state lying on the equator of the Bloch sphere, such as realized in a coherent two-component Bose–Einstein condensate, is teleported onto a distant spin coherent state using only elementary operations and measurements. The scheme works in the regime beyond the standard continuous variables approximation based on the Holstein–Primakoff transformation. We analyze the error of the protocol with the number of particles N in the spin coherent state under decoherence and find that it scales favorably with N. The simplicity of the operations involved and the robustness under decoherence should make the protocol suitable under realistic experimental conditions.

Highlights

Quantum mechanics is typically associated with the microscopic world, where phenomena such as superposition and entanglement occur for few-particle systems, but become difficult to observe when scaled up to macroscopic objects
It has become clear in recent years that even macroscopic objects can behave quantum mechanically, and possess significant amounts of entanglement [1, 2]
We have introduced a protocol that can teleport a spin coherent state lying on an arbitrary position on the Bloch sphere between two parties

Summary

Introduction

Quantum mechanics is typically associated with the microscopic world, where phenomena such as superposition and entanglement occur for few-particle systems, but become difficult to observe when scaled up to macroscopic objects. The method encodes qubit information on spin coherent states, which can involve either spinor Bose-Einstein condensates (BECs) or atomic ensembles. [21] is that such “BEC qubits” can be used with analogous properties to standard qubits, such that various quantum algorithms and quantum communication [22] can be performed using these states Such spin coherent states are generally thought to be “classical” in the sense that the fluctuations of normalized spin variables Sj/N. [23], it was shown that quantum effects such as entanglement can be generated between several such BEC qubits [24], and quantum algorithms could be performed provided an equivalent algorithm could be found It is clear from the structure of (1) that the quantum information is duplicated.

The teleportation protocol

Comparison to an all-classical strategy and decoherence

Conclusions