arXiv subjects

Haruka Tanji

Publications and source records attributed to Haruka Tanji.

2 recordsLinked to original sources

arXiv2008

Heralded single-magnon quantum memory for photon polarization states

We demonstrate a heralded quantum memory based on mapping of a photon polarization state onto a single collective-spin excitation (magnon) shared between two spatially overlapped atomic ensembles. The polarization fidelity is measured by quantum state tomography to be above 90(2)% for any input polarization, which far exceeds the classical limit of 2/3. The process also constitutes a quantum non-destructive probe that detects and regenerates a photon without touching its - potentially undetermined - polarization.

quant-ph↗

arXiv2008

Simplified measurement of the Bell parameter within quantum mechanics

We point out that, if one accepts the validity of quantum mechanics, the Bell parameter for the polarization state of two photons can be measured in a simpler way than by the standard procedure [Clauser, Horne, Shimony, and Holt, Phys. Rev. Lett. 23, 880 (1969)]. The proposed method requires only two measurements with parallel linear-polarizer settings for Alice and Bob at 0 and 45 degrees, and yields a significantly smaller statistical error for a large Bell parameter.

quant-ph↗