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arXiv · 1403.4857

Photonic quantum walk in a single beam with twisted light

Filippo Cardano·Francesco Massa·Ebrahim Karimi·Sergei Slussarenko·Domenico Paparo·Corrado de Lisio·Fabio Sciarrino·Enrico Santamato·Lorenzo Marrucci
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Abstract

Inspired by the classical phenomenon of random walk, the concept of quantum walk has emerged recently as a powerful platform for the dynamical simulation of complex quantum systems, entanglement production and universal quantum computation. Such a wide perspective motivates a renewing search for efficient, scalable and stable implementations of this quantum process. Photonic approaches have hitherto mainly focused on multi-path schemes, requiring interferometric stability and a number of optical elements that scales quadratically with the number of steps. Here we report the experimental realization of a quantum walk taking place in the orbital angular momentum space of light, both for a single photon and for two simultaneous indistinguishable photons. The whole process develops in a single light beam, with no need of interferometers, and requires optical resources scaling linearly with the number of steps. Our demonstration introduces a novel versatile photonic platform for implementing quantum simulations, based on exploiting the transverse modes of a single light beam as quantum degrees of freedom.

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Filippo Cardano, Francesco Massa, Ebrahim Karimi, Sergei Slussarenko, Domenico Paparo, Corrado de Lisio, Fabio Sciarrino, Enrico Santamato, Lorenzo Marrucci. 2014-03-19. Photonic quantum walk in a single beam with twisted light. https://doi.org/10.1126/sciadv.1500087

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