Interfacing single photons and electrons is a crucial ingredient for sharing quantum information between remote solid-state qubits. Semiconductor nanowires offer the unique possibility to combine optical quantum dots with avalanche photodiodes, thus enabling the conversion of an incoming single photon into a macroscopic current for efficient electrical detection. Currently, millions of excitation events are required to perform electrical read-out of an exciton qubit state. Here we demonstrate multiplication of carriers from only a single exciton generated in a quantum dot after tunneling into a nanowire avalanche photodiode. Due to the large amplification of both electrons and holes (> 10^4), we reduce by four orders of magnitude the number of excitation events required to electrically detect a single exciton generated in a quantum dot. This work represents a significant step towards single-shot electrical read-out and offers a new functionality for on-chip quantum information circuits.
@article{arxiv.1204.4131,
title = {Avalanche amplification of a single exciton in a semiconductor nanowire},
author = {Gabriele Bulgarini and Michael E. Reimer and Moïra Hocevar and Erik P. A. M. Bakkers and Leo P. Kouwenhoven and Val Zwiller},
journal= {arXiv preprint arXiv:1204.4131},
year = {2015}
}