Determination of any pure spatial qudits from a minimum number of measurements by phase-stepping interferometry
We present a proof-of-principle demonstration of a method to characterize any pure spatial qudit of arbitrary dimension d, which is based on the classic phase-shift interferometry technique. In the proposed scheme a total of only 4d measurement outcomes are needed, implying a significant reduction w...
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| Autores principales: | , , , |
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| Formato: | Articulo Preprint |
| Lenguaje: | Inglés |
| Publicado: |
2017
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| Materias: | |
| Acceso en línea: | http://sedici.unlp.edu.ar/handle/10915/99211 https://ri.conicet.gov.ar/11336/50049 |
| Aporte de: |
| Sumario: | We present a proof-of-principle demonstration of a method to characterize any pure spatial qudit of arbitrary dimension d, which is based on the classic phase-shift interferometry technique. In the proposed scheme a total of only 4d measurement outcomes are needed, implying a significant reduction with respect to the standard schemes for quantum-state tomography which require on the order of d2. By using this technique, we have experimentally reconstructed a large number of states ranging from d=2 up to 14 with mean fidelity values higher than 0.97. For that purpose the qudits were codified in the discretized transverse-momentum position of single photons, once they are sent through an aperture with d slits. We provide an experimental implementation of the method based in a Mach-Zehnder interferometer, which allows one to reduce the number of measurement settings to four since the d slits can be measured simultaneously. Furthermore, it can be adapted to consider the reconstruction of the unknown state from the outcome frequencies of 4d-3 fixed projectors independently of the encoding or the nature of the quantum system, allowing one to implement the reconstruction method in a general experiment. |
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