Experimental demonstration of a Hadamard gate for coherent state qubits

TL;DR

This paper reports the experimental realization of a probabilistic Hadamard gate for coherent state qubits using linear optics, non-classical resources, and joint measurements, with full state tomography and fidelity analysis.

Contribution

It presents the first experimental demonstration of a Hadamard gate for coherent state qubits with detailed characterization and simulation of fidelity across the Bloch sphere.

Findings

Successful implementation of a probabilistic Hadamard gate

Full quantum state tomography of output states

Fidelity simulation across the Bloch sphere

Abstract

We discuss and experimentally demonstrate a probabilistic Hadamard gate for coherent state qubits. The scheme is based on linear optical components, non-classical resources and the joint projective action of a photon counter and a homodyne detector. We experimentally characterize the gate for the coherent states of the computational basis by full tomographic reconstruction of the transformed output states. Based on the parameters of the experiment we simulate the fidelity for all coherent state qubits on the Bloch sphere.