Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

Photonics for Quantum (PfQ)

Single photon frequency shifting and all-optic universal fine structure eraser for quantum dots

Sonell Malik, Maeve Wentland, Andreas Fognini, Dan Dalacu, Philip J. Poole, Val Zwiller, Michael E. Reimer

Published Aug 2, 2024• 0 citations
Publisher

Abstract

Highly entangled photon sources play a crucial role in advancing the capabilities of quantum networks. In this context, we introduce an advanced scheme aimed at improving entanglement of photons emitted from quantum dots based on the framework proposed by Fognini et al. (2018). We propose a setup with reduced physical footprint which employs one electro-optic modulator strategically to enhance entanglement, mitigating the detrimental effects of fine structure splitting (FSS) observed in quantum dots that contribute to the degradation of entanglement.

DOI
10.1117/12.3027157

Related papers

Coherent spectral shift of single photons from a quantum dot

Sanjay Kapoor, Aleksander Rodek, Michał Mikołajczyk +5 more

We demonstrate tunable frequency shifting of photons emitted from a quantum dot source using electro-optic phase modulation while preserving the purity and indistinguishability of the source.

Quantum 2.0 Conference and Exhibition•Jan 1, 2025•0 citations

Hyper-entangled photon pairs from single quantum dots

Geng Chen, Chuan‐Feng Li, Zhen−Qiang Yin +3 more

We propose a scheme to generate hyper-entangled photon pairs from single quantum dots (SQDs). Single photons emitted by SQD are manipulated to be entangled after post-selection. Crucially, exciton fine-structure splitting, which was previously deemed undesirable in similar schemes, is used here to produce photon pairs entangled in both frequency and polarization degrees of freedom. This hyper-entangled two-photon state is potentially more powerful than a normal entangled state for quantum state engineering and quantum information processing.

Europhysics Letters (EPL)•Feb 1, 2010•5 citations

Electro-optic rotating half-waveplate for a quantum dot fine-structure eraser

Simon Daley

Quantum dots are a promising source of entangled photon pairs. Recent advances have \nshown nearly dephasing-free entanglement from quantum dots embedded in semiconductor \nnanowires. An outstanding challenge with these sources is the presence of the so-called \n fine-structure splitting, which is the lifting of spin degeneracy of the exciton state due to \nquantum dot potential asymmetry. This fine-structure splitting causes the output state \nto precess rapidly, which is degrades the quality of measured entanglement due to nite \ndetector temporal response and is undesirable for applications where preparation of a \nconsistent state is needed. The effects of fine-structure splitting can be \\erased" once the \nphotons have been emitted using a flexible all-optical approach. This optical fine-structure \neraser scheme requires a rapidly rotating half-waveplate, which cannot be implemented \nwith commercially available off-the-shelf systems. This thesis presents the operation of \nan electro-optic modulator which can emulate a rotating half-waveplate at the required \nspeeds, and demonstrates frequency conversion with an efficiency of 92%.

•Aug 28, 2019•1 citation

Frequency Shifting a Single Photon by Electro-Optic Modulation

Michael Kobierski

Entanglement is a rare resource only a select few people worldwide can create. Its fundamentally non-classical behavior seeds a tree of ideas from which transformative technologies in information processing, communication, and imaging grow. Particularly interesting is entanglement between photons in a pair made by a quantum dot, the most competitive contender among quantum photonic devices. \n \nA strength of semiconductor quantum dots is their deterministic reliability and potential for production at scale. The associated price is anchored in their inherent flaw: sensitivity to imperfections in their shape puts the entanglement they generate in motion. Thus, unless a specific entangled photon pair is caught at just the right moment, it will appear as though it is in fact not entangled at all. \n \nIngenious methods for making quantum dots perfect again have been devised,almost exclusively built around reshaping the dot by physical, electric, or magnetic means. One completely different proposal stands out, which instead stops the entanglement's motion once it has already been created. As a purely optical technique it can be used for any quantum dot and is completely non-intrusive. This is the method of the rotating half-wave plate. \n \nThe entanglement between photons in a pair revolves up to a few billion times per second and halting it requires a correction one-half that rate. Physically spinning a crystal waveplate at that tremendous speed is impossible, but if the properties of a crystal are spun in an identical way such quickly varying entanglement can be restored to its starting point with ease. This is the principle of electro-optic modulation. \n \nThis thesis shows the very first demonstration of slowing the frequency of single photons in a stream by using an electro-optical rotating half-wave plate prototype. Initial results show a reduction in frequency by 127.75 million oscillations per second. Any quantum dot whose entanglement precesses no more quickly than 255.5 MHz can thus directly make use of the technique contained herein.

•Jan 21, 2020•0 citations

Serrodyne electro-optic frequency shift of single photons from a solid-state emitter

Sanjay Kapoor, Aleksander Rodek, Michał Mikołajczyk +5 more

We demonstrate the frequency shifting of photons emitted from a quantum dot source using electro-optic serrodyne modulation while preserving the purity and indistinguishability of the source.

•Jan 1, 2025•0 citations

Phase compensation enhancement of photon pair entanglement generated from biexciton decay in quantum dots

Zong‐Quan Zhou, Chuan‐Feng Li, Geng Chen +4 more

Exciton fine-structure splittings within quantum dots introduce phase differences between the two biexciton decay paths that greatly reduce the entanglement of photon pairs generated via biexciton recombination. We analyze this problem in the frequency domain and propose a practicable method to compensate the phase difference by inserting a spatial light modulator, which substantially improves the entanglement of the photon pairs without any loss.

arXiv:0909.0078•Physical Review A•Jun 10, 2010•10 citations
Highly entangled photon sources play a crucial role in advancing the capabilities of quantum networks. In this context, we introduce an advanced scheme aimed at improving entanglement of photons emitted from quantum dots based on the framework proposed by Fognini et al. (2018). We propose a setup with reduced physical footprint which employs one electro-optic modulator strategically to enhance entanglement, mitigating the detrimental effects of fine structure splitting (FSS) observed in quantum dots that contribute to the degradation of entanglement.
We propose a scheme to generate hyper-entangled photon pairs from single quantum dots (SQDs). Single photons emitted by SQD are manipulated to be entangled after post-selection. Crucially, exciton fine-structure splitting, which was previously deemed undesirable in similar schemes, is used here to produce photon pairs entangled in both frequency and polarization degrees of freedom. This hyper-entangled two-photon state is potentially more powerful than a normal entangled state for quantum state engineering and quantum information processing.
Quantum dots are a promising source of entangled photon pairs. Recent advances have \nshown nearly dephasing-free entanglement from quantum dots embedded in semiconductor \nnanowires. An outstanding challenge with these sources is the presence of the so-called \n fine-structure splitting, which is the lifting of spin degeneracy of the exciton state due to \nquantum dot potential asymmetry. This fine-structure splitting causes the output state \nto precess rapidly, which is degrades the quality of measured entanglement due to nite \ndetector temporal response and is undesirable for applications where preparation of a \nconsistent state is needed. The effects of fine-structure splitting can be \\erased" once the \nphotons have been emitted using a flexible all-optical approach. This optical fine-structure \neraser scheme requires a rapidly rotating half-waveplate, which cannot be implemented \nwith commercially available off-the-shelf systems. This thesis presents the operation of \nan electro-optic modulator which can emulate a rotating half-waveplate at the required \nspeeds, and demonstrates frequency conversion with an efficiency of 92%.
Entanglement is a rare resource only a select few people worldwide can create. Its fundamentally non-classical behavior seeds a tree of ideas from which transformative technologies in information processing, communication, and imaging grow. Particularly interesting is entanglement between photons in a pair made by a quantum dot, the most competitive contender among quantum photonic devices. \n \nA strength of semiconductor quantum dots is their deterministic reliability and potential for production at scale. The associated price is anchored in their inherent flaw: sensitivity to imperfections in their shape puts the entanglement they generate in motion. Thus, unless a specific entangled photon pair is caught at just the right moment, it will appear as though it is in fact not entangled at all. \n \nIngenious methods for making quantum dots perfect again have been devised,almost exclusively built around reshaping the dot by physical, electric, or magnetic means. One completely different proposal stands out, which instead stops the entanglement's motion once it has already been created. As a purely optical technique it can be used for any quantum dot and is completely non-intrusive. This is the method of the rotating half-wave plate. \n \nThe entanglement between photons in a pair revolves up to a few billion times per second and halting it requires a correction one-half that rate. Physically spinning a crystal waveplate at that tremendous speed is impossible, but if the properties of a crystal are spun in an identical way such quickly varying entanglement can be restored to its starting point with ease. This is the principle of electro-optic modulation. \n \nThis thesis shows the very first demonstration of slowing the frequency of single photons in a stream by using an electro-optical rotating half-wave plate prototype. Initial results show a reduction in frequency by 127.75 million oscillations per second. Any quantum dot whose entanglement precesses no more quickly than 255.5 MHz can thus directly make use of the technique contained herein.