Polarization of particles with spin unity

B. Z. Kopeliovich

Matteo P. Pennacchietti, Mohd Zeeshan, Brady Cunard +6 more

Quantum dots (QDs) embedded inside indium-phosphide (InP) nanowires have the potential to be bright, on-demand sources of perfect polarization-entangled photon pairs fabricated with near-unity yields. However, to date very high degrees of entanglement have not yet been measured from such devices. By performing quantum state tomography with state-of-the-art superconducting nanowire single-photon detectors (SNSPDs) and two-photon resonant excitation of the QD, we show that these sources are indeed capable of producing near-unity entangled photon pairs. We measure a raw peak fidelity of 97.5% +/- 0.8% and a lifetime-weighted fidelity of 0.94% +/- 0.04%. These results conclusively demonstrate that the majority of the degradation from unity-measured entanglement fidelity in earlier studies was not due to spin-spin dephasing from the large 9/2 nuclear spin of indium. These results solidify InP nanowire QDs as a promising platform for future quantum photonics applications.

Hans Paetz gen. Schieck

C. J. Mullin

T. Morita

A lattice gas model equivalent to the t-J model is proposed, in which the spins are represented by Bose particles with spin and the holes by Fermi particles with spin. In the zero hole density, the model reduces to a lattice gas of Bose particles with spin, equivalent to the Heisenberg model, where the average occupation number of a lattice site is unity, while a lattice site can accomodate two particles.

Charles J. Mullin, Joseph M. Keller, C. L. Hammer +1 more