Generation and tomography of arbitrary qubit states in a transient collective atomic excitation

Abstract

We demonstrate the generation of heralded Fock-basis qubits $(a|0⟩+b|1⟩)$ from transient collective spin excitations in a hot atomic vapor. The collective spin excitation is heralded by Raman-scattered photons in a four-wave mixing process seeded by a weak coherent optical excitation. The amplitude and phase of the seed field allow arbitrary control over the qubit coefficients. The state of the ensemble is read out optically and then characterized using balanced homodyne tomography. This work represents a step towards quantum engineering of collective atomic spin states.

4 pages, 3 figures

References in corpus (2)

• Diluted maximum-likelihood algorithm for quantum tomography
• Linear-optical processing cannot increase photon efficiency

Cited by in corpus (4)

• Generating quantum correlated twin beams by four-wave mixing in hot cesium vapor
• Quantum beam splitter for orbital angular momentum of light: quantum correlation by four-wave mixing operated in a nonamplifying regime
• Arbitrary Multi-Qubit Generation
• Quantum coherence of an orbital angular momentum multiplexed continuous-variable entangled state