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arXiv · 1306.0619

Direct Measurement of a 27-Dimensional Orbital-Angular-Momentum State Vector

Mehul Malik·Mohammad Mirhosseini·Martin P. J. Lavery·Jonathan Leach·Miles J. Padgett·Robert W. Boyd
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Abstract

The measurement of a quantum state poses a unique challenge for experimentalists. Recently, the technique of "direct measurement" was proposed for characterizing a quantum state in-situ through sequential weak and strong measurements. While this method has been used for measuring polarization states, its real potential lies in the measurement of states with a large dimensionality. Here we show the practical direct measurement of a high-dimensional state vector in the discrete basis of orbital-angular momentum. Through weak measurements of orbital-angular momentum and strong measurements of angular position, we measure the complex probability amplitudes of a pure state with a dimensionality, d=27. Further, we use our method to directly observe the relationship between rotations of a state vector and the relative phase between its orbital-angular-momentum components. Our technique has important applications in high-dimensional classical and quantum information systems, and can be extended to characterize other types of large quantum states.

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Mehul Malik, Mohammad Mirhosseini, Martin P. J. Lavery, Jonathan Leach, Miles J. Padgett, Robert W. Boyd. 2013-06-03. Direct Measurement of a 27-Dimensional Orbital-Angular-Momentum State Vector. https://doi.org/10.1038/ncomms4115

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