Research in quantum communication

Quantum communication research within WACQT comprises a number of research groups that work with various aspects of quantum cryptography: quantum key distribution, entangled photon sources, increasing the transfer rate, etc. 
For a general introduction to quantum communication, please go to page Quantum communication.

Coordinators of efforts in quantum communication:
Katia Gallo,, +46 76 517 33 15
Stefan Kröll,​. +46 46 222 96 26

Research projects in quantum communication

Integrated quantum pho​tonics

Hybrid quantum photonic c​ircuits
Nonlinearities at the single-photon level is crucial to reduce the resource overhead in quantum gates and teleportation. This project will demonstrate novel architectures for nonlinear interaction between photons, allowing to probe new regimes of light-matter interaction physics.
Principal investigator: Ali Elshaari, KTH
Postdoc: Jun Gau, KTH, PhD student: Govind Krishna, KTH 

Scalable quantum information processing using ultralow-loss silicon nitride nanophotonics
This project aims at attaining 15 dB two-mode squeezing on chip, scaling to 100 qumodes using quantum microcombs, and assessing a practical interface with programmable linear circuits.
PhD student: Sara Persia, Chalmers 

High brightness entangled photon-pair sources in periodically poled LiNbO3-on-insulator
This project leverages the know-how on lithium niobate nanophotonics, periodic poling, and integrated nonlinear optics, with the aim to demonstrate a 10 MHz entangled-photon source based on spontaneous parametric downconversion at 1550 nm.
Principal investigators: Katia Gallo and Ashraf El Hassan, KTH
PhD student: Tiantong Li, KTH 

Sources of polarization-entangled photon pairs based on the nonlinearities of semiconductor nano-waveguides
The project’s aim is to develop laser-pumped arrays of nano-waveguide structures to provide polarization-entangled photons for use in systems for quantum key distribution.
Principal investigators: Marcin Swillo and Gunnar Björk, KTH
PhD student: Albert Peralta Amores, KTH 

Quantum key distribution

Quantum-dot based photon sources for the generation of highly indistinguishable and entangled photon pairs
The project focuses on generation of time-energy- and time-bin-entangled photon clusters that would enable the implementation of a quantum version of phase-shift keying. Such encoding is compatible with standard telecommunication fibre-optics network.
Principal investigator: Ana Predojevi, Stockholm University
Postdoc: Laia Gines, Stockholm University 

Multipartite photon entanglement in two-dimensional nonlinear lattices
The project aims at developing novel monolithic photon sources based on purely nonlinear photonic lattices in periodically poled materials to produce multiphoton entanglement and couple flying qubits at telecom wavelengths to stationary qubits in the near-infrared range.
Principal investigator: Katia Gallo, KTH
Postdoc: Hammad Anwer, KTH 

Quantum communication based on few-mode and multi-core optical fibers
The main goal of this project is experimental demonstrations that high-dimensional photonic quantum systems (qudits) can be successfully generated and propagated over long distances in novel few-mode and multi-core fibres.
Principal investigator: Guilherme Xavier, Linköping University
PhD student: Alvaro Alarcón, Linköping University 

Time-bin spatially-structured photonic qudits
This project studies the generation, transmission, and detection of spatially encoded states over few-mode fibres. The goal is to create a fully scalable method to increase the dimensionality of the photonic quantum systems by coherently combining time-bin encoding to the spatial photonic qudits.
Principal investigator: Guilherme Xavier, Linköping University
PhD student: Daniel Spegel-Lexne, Linköping University 

Development of an entanglement-based, device independent quantum-key distribution system
The underlying idea is to use Bell tests to ensure that the encryption key is shared by only the legitimate receivers, even if the key generating device is made by an adverse, eavesdropping party. Learn more in this short film ​by Alban Seguinard.
Principal investigator: Mohamed Bourennane, Stockholm University
PhD student: Alban Seguinard, Stockholm University 

Network quantum correlation
The project goal is to use novel aspects in the field of quantum communication and quantum networks and investigate the development of a prototype for long-distance quantum communication to a practical level suitable for deployment in industry.
Principal investigators: Mohamed Bourennane, Stockholm University and Michele Luvisotto, Hitachi Energy
Industrial PhD student: Emil Håkansson, Stockholm University/Hitachi Energy 

Security analysis toolbox for quantum cryptography

Quantum key distribution has an information-theoretically proven security principle, but in practice, one also needs to demonstrate the security of its implementation. The aim of this project is to investigate the security of practical quantum cryptography protocols.
Principal investigator: Mohamed Bourennane, Stockholm University
Postdoc: Position expected to be filled within soon 

Metropolitan quantum network
This project will further develop polarisation-stabilisation schemes for deployed optical fibres and fabricate and implement a new generation of single- and entangled-photon sources based on quantum dots in positioned nanostructures. These devices will be used to operate the quantum network linking KTH to Ericsson and to implement quantum-communication protocols.
Principal investigator: Val Zwiller, KTH
PhD student: Stéphane Cohen, KTH 

Microwave-to-optical transduction

Quantum microwave-nanophotonic transducer
This project develops transducers between microwave and optical quantum states. Such devices could be used to connect several superconducting quantum systems into a larger quantum processor. Read more
Principal investigator: Raphaël Van Laer, Chalmers
Involved PhD students: Johan Kolvik, Joey Frey, Paul Burger, and Trond Haug, Chalmers 

Enhanced phonon-photon coupling with ferroelectric domain structures
The goal of this project is to develop models and simulations for the nonlinear optical, electrical, and mechanical response of ferroelectric domains and domain walls in periodically poled lithium niobate (PPLN) and its isomorphs. This theoretical groundwork will e.g. help us identify potential novel configurations for quantum acoustics and optics experiments in PPLN devices.
Principal investigator: Egor Babaev, KTH
PhD student: Anton Talkachov, KTH

Page manager Published: Fri 28 Oct 2022.