Real-time imaging of spin-to-orbital angular momentum hybrid remote state preparation

Quantum teleportation is a process in which an unknown quantum state is transferred between two spatially separated subspaces of a bipartite quantum system which share an entangled state and communicate classically. In the case of photonic states, this process is probabilisti c due to the impossibility of performing a two-particle complete Bell state analysis with linear optics. In order to achieve a deterministic teleportation scheme, harnessing other degrees of freedom of a single particle, rathe r than a third particle, has been proposed. Indeed, this leads to a novel type of deterministic teleportation scheme, the so-called hybrid teleportation. Here we report the first realization of photonic hybrid quantum teleportat ion 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 teleported states are visualized in real-time by means of an intensified CCD camera. The quality of teleported states is verified by performing quantum state to mography, which confirms an average fidelity higher than 99.4%. We believe this experiment paves the route towards a novel way of quantum communication in which encryption and decryption are carried out in naturally different Hilbert spaces, and therefore may provide means of enhancing security. Entanglement is one of the most interesting aspects of quantum mechanics and is at the heart of several quantum paradoxes, such as the Einstein-Podolsky-Rosen (EPR) paradox [1], Hardy paradox [2], and Leggett’s inequalities [3]. One of the features that is made possible via entanglement is the ability to teleport arbitrary quantum states. In gene ral, a quantum teleportation scheme describes how to transmit a quantum state between two spatially separated participants, usually called Alice and Bob ‐ hereafter referred to as A and B, respectively. In 1997, Bennett and coworkers proposed the first quantum state teleportation scheme, which was based on three spin-half particles [4]. In their scheme, particles o ne and two are in an EPR-entangled state in the spin degree of freedom (DOF). Particle three, Charlie (C), is in a quantum state |�i , which in general is unknown. A has particles one and three while B has particle two of the entangled pair. In order to transmit the quantum state|�i from A to B, A performs a joint Bell-state measurement on particles one and three. She then sends B a classical message with the measurement outcome, which contains two classical bits. With this information B is able to perform a unitary operation to reconstruct the quantum state|�i . This scheme needs three particles and uses their spin DOF to transmit the non-classical information. Later on, however, different theoretical and experimental teleportation schemes based on use of multiple particles and different degrees of freedom were proposed in the literature [5‐ 9]. Among those, schemes that are based on different degrees of freedom, i.e. hybrid teleportation, received particula r attention. This is due to the deterministic nature of these schemes, in contrast to implementations based on multiple particles ‐ recall the impossibility of performing two-particle complete Bell-state measurements with linear optics. In addition, c om

[1]  C. Ross Found , 1869, The Dental register.

[2]  Zach DeVito,et al.  Opt , 2017 .

[3]  Andrew G. Glen,et al.  APPL , 2001 .