arXiv subjects

Michael E. Reimer

Publications and source records attributed to Michael E. Reimer.

21 records · Page 2Linked to original sources

arXiv2012

Bright single-photon sources in bottom-up tailored nanowires

The ability to achieve near-unity light extraction efficiency is necessary for a truly deterministic single photon source. The most promising method to reach such high efficiencies is based on embedding single photon emitters in tapered photonic waveguides defined by top-down etching techniques. However, light extraction efficiencies in current top-down approaches are limited by fabrication imperfections and etching induced defects. The efficiency is further tempered by randomly positioned off-axis quantum emitters. Here, we present perfectly positioned single quantum dots on the axis of a tailored nanowire waveguide using bottom-up growth. In comparison to quantum dots in nanowires without waveguide, we demonstrate a 24-fold enhancement in the single photon flux, corresponding to a light extraction efficiency of 42 %. Such high efficiencies in one-dimensional nanowires are promising to transfer quantum information over large distances between remote stationary qubits using flying qubits within the same nanowire p-n junction.

cond-mat.mes-hall↗

arXiv2010

Single photon emission and detection at the nanoscale utilizing semiconductor nanowires

We report recent progress toward on-chip single photon emission and detection in the near infrared utilizing semiconductor nanowires. Our single photon emitter is based on a single InAsP quantum dot embedded in a p-n junction defined along the growth axis of an InP nanowire. Under forward bias, light is emitted from the single quantum dot by electrical injection of electrons and holes. The optical quality of the quantum dot emission is shown to improve when surrounding the dot material by a small intrinsic section of InP. Finally, we report large multiplication factors in excess of 1000 from a single Si nanowire avalanche photodiode comprised of p-doped, intrinsic, and n-doped sections. The large multiplication factor obtained from a single Si nanowire opens up the possibility to detect a single photon at the nanoscale.

cond-mat.mes-hall↗

arXiv2007

Voltage Induced Hidden Symmetry and Photon Entanglement Generation in a Single, Site-Selected Quantum Dot

Present proposals for the realisation of entangled photon pair sources using the radiative decay of the biexciton in semiconductor quantum dots are limited by the need to enforce degeneracy of the two intermediate, single exciton states. We show how this requirement is lifted if the biexciton binding energy can be tuned to zero and we demonstrate this unbinding of the biexciton in a single, pre-positioned InAs quantum dot subject to a lateral electric field. Full Configuration-Interaction calculations are presented that reveal how the biexciton is unbound through manipulation of the electron-hole Coulomb interaction and the consequent introduction of Hidden Symmetry.

quant-ph↗