Description
Qudits are the higher-dimensional version of the two-level qubits. Measuring a qudit results into any of $d$ orthogonal states, thereby providing a larger Hilbert space with increased information capacity for computation and communication applications. One natural route to encoding high-dimensional quantum information is through the transverse spatial structure of light, with each basis state realized as a distinct transverse mode of the optical field. This experimental project uses multi-plane light conversion (MPLC), as an implementation of a single-qudit gate operation. MPLC can, in principle, apply any arbitrary unitary transformation through a series of phase masks on a spatial light modulator. We use MPLC to create and transform Laguerre–Gaussian modes, an orthogonal family of beams carrying orbital angular momentum. We are able to prepare single-qudit states of a chosen dimension, and transform these through a series of Pauli $\hat{X}$ and $\hat{Z}$ gates. Cascading the $\hat{X}$ gate and $\hat{Z}$ gate allows for investigation of the Weyl commutation relation. We characterize the cascaded operations classically via digital holography, which recovers the full complex field of the output after the two gate operations. Our work helps move towards scalable and high-fidelity gate operations, which are key building blocks for the next generation of photonic quantum information processing.
| I am the presenting author | Yes |
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