TY - BOOK
T1 - Towards a room temperature single photon source based on atomic vapour
AU - Zugenmaier, Michael Viktor Alban
PY - 2018
Y1 - 2018
N2 - Efficient quantum communication over long distances requires quantum repeaters
along the communication line. Quantum repeaters based on room temperature
systems offer advantages due to their scalability. However, atomic motion
has until now prevented these systems to reach long lifetimes of heralded
single collective excitations in room temperature systems. We study the characteristics
of vapour cells with anti-relaxation coating which allows for long lifetimes.
We demonstrate efficient heralding and readout of single collective excitations
created in warm caesium vapour. Using the concept of motional averaging,
we can achieve a lifetime of the collective excitation of 0.27 0.04 ms, two
orders of magnitude longer than previous warm vapour experiments on the
single photon level. We verify the non-classicality of the correlations between
heralding and readout fields by a significant violation of the Cauchy-Schwarz
inequality with R = (1.4 0.1) > 1. The spectral and temporal analysis of
the noise contributions that contaminate the single photon readout allows us to
identify leakage of excitation light and intrinsic four-wave mixing as two main
contributions. In a proof-of-principle experiment we confirm an experimental
solution to suppress the four-wave mixing noise. We discuss possibilities to
identify and possibly eliminate the remaining noise sources and thus with an
improved setup to advance towards the applicability as an on-demand single
photon source.
AB - Efficient quantum communication over long distances requires quantum repeaters
along the communication line. Quantum repeaters based on room temperature
systems offer advantages due to their scalability. However, atomic motion
has until now prevented these systems to reach long lifetimes of heralded
single collective excitations in room temperature systems. We study the characteristics
of vapour cells with anti-relaxation coating which allows for long lifetimes.
We demonstrate efficient heralding and readout of single collective excitations
created in warm caesium vapour. Using the concept of motional averaging,
we can achieve a lifetime of the collective excitation of 0.27 0.04 ms, two
orders of magnitude longer than previous warm vapour experiments on the
single photon level. We verify the non-classicality of the correlations between
heralding and readout fields by a significant violation of the Cauchy-Schwarz
inequality with R = (1.4 0.1) > 1. The spectral and temporal analysis of
the noise contributions that contaminate the single photon readout allows us to
identify leakage of excitation light and intrinsic four-wave mixing as two main
contributions. In a proof-of-principle experiment we confirm an experimental
solution to suppress the four-wave mixing noise. We discuss possibilities to
identify and possibly eliminate the remaining noise sources and thus with an
improved setup to advance towards the applicability as an on-demand single
photon source.
UR - https://rex.kb.dk/primo-explore/fulldisplay?docid=KGL01011892359&context=L&vid=NUI&search_scope=KGL&tab=default_tab&lang=da_DK
M3 - Ph.D. thesis
BT - Towards a room temperature single photon source based on atomic vapour
PB - The Niels Bohr Institute, Faculty of Science, University of Copenhagen
ER -