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arXiv · 1512.02696

Cyclic transformation of orbital angular momentum modes

Florian Schlederer·Mario Krenn·Robert Fickler·Mehul Malik·Anton Zeilinger
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Abstract

The spatial modes of photons are one realization of a QuDit, a quantum system that is described in a D-dimensional Hilbert space. In order to perform quantum information tasks with QuDits, a general class of D-dimensional unitary transformations is needed. Among these, cyclic transformations are an important special case required in many high-dimensional quantum communication protocols. In this paper, we experimentally demonstrate a cyclic transformation in the high-dimensional space of photonic orbital angular momentum (OAM). Using simple linear optical components, we show a successful four-fold cyclic transformation of OAM modes. Interestingly, our experimental setup was found by a computer algorithm. In addition to the four-cyclic transformation, the algorithm also found extensions to higher-dimensional cycles in a hybrid space of OAM and polarization. Besides being useful for quantum cryptography with QuDits, cyclic transformations are key for the experimental production of high-dimensional maximally entangled Bell-states.

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Florian Schlederer, Mario Krenn, Robert Fickler, Mehul Malik, Anton Zeilinger. 2015-12-08. Cyclic transformation of orbital angular momentum modes. https://doi.org/10.1088/1367-2630%2F18%2F4%2F043019

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