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arXiv · 1703.02786

Negative Wigner function at telecommunication wavelength from homodyne detection

Christoph Baune·Jaromir Fiurasek·Roman Schnabel
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Abstract

Quantum states of light having a Wigner function with negative values represent a key resource in quantum communication and quantum information processing. Here, we present the generation of such a state at the telecommunication wavelength of 1550nm. The state is generated by means of photon subtraction from a weakly squeezed vacuum state and is heralded by the `click' of a single photon counter. Balanced homodyne detection is applied to reconstruct the Wigner function, also yielding the state's photon number distribution. The heralding photons are frequency up-converted to 532nm to allow for the use of a room-temperature (silicon) avalanche photo diode. The Wigner function reads W(0,0)=-0.063 +/- 0.004 at the origin of phase space, which certifies negativity with more than 15 standard deviations.

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Christoph Baune, Jaromir Fiurasek, Roman Schnabel. 2017-03-08. Negative Wigner function at telecommunication wavelength from homodyne detection. https://doi.org/10.1103/physreva.95.061802

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