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Paper on the optimality of quantum enhancement in the GEO600 gravitational wave detector published
October 11, 2013
It is theoretically demonstrated that the recently reported quantum-noise-limited sensitivity of the squeezed-light-enhanced German-British gravitational wave detector GEO 600 is exceedingly close to the fundamental theoretical bound, given the present amount of optical loss. Furthermore, it is proven that the employed combination of a bright coherent state and a squeezed vacuum state is generally the optimum practical approach for phase estimation with high precision on absolute scales. [Demkowicz-Dobrzanski et al, Phys. Rev. A 88, 041802(R) (2013)]
First quantum metrological protocol which accounts for the
uncorrelated noise
September 18, 2013
Janek Kolodynski (PhD student from our TEAM) in collaboration
with researchers from the ICFO Institute in Barcelona, has proposed
the first quantum metrological protocol which accounts for the
uncorrelated noise affecting independently each particle within the
setup but nevertheless allows for a quantum enhancement of measurement
precision that scales limitlessly with the number of particles
involved. Results of this work have recently been published in
reputable journal Physical Review Letters. Congratulations!
3rd International Conference on Quantum Cryptography
August 5-9, 2013
3rd edition of the annual Intenational Conference on Quantum Cryptography - QCrypt2013 - has been held in Waterloo, Canada. Our team member Mikołaj Lasota contributed with a poster entitled Criteria for realistic single photon sources in quantum repeater applications.
New article has appeared
June 28, 2013
An article Quantum key distribution with realistic heralded single-photon sources by Mikołaj Lasota, Rafał Demkowicz-Dobrzański and Konrad Banaszek has appeared in International Journal of Quantum Information.
13th International Conference on Squeezed States and Uncertainty Relations
June 24-28, 2013
Mikołaj Lasota has participated in the 13th International Conference on Squeezed States and Uncertainty Relations (ICSSUR2013), which was held in Sheraton-Carlton Hotel in Nuremberg, Germany. During the event Mikołaj presented a scientific poster Criteria for realistic single photon sources in quantum repeater applications.
CQO X- QIM 2
June 17-20, 2013
Two of our PhD students, Radosław Chrapkiewicz and Marcin Jarzyna
participated in two major conferences in the quantum optics and
information science field, Coherence and Quantum Optics and Quantum
Information and Measurement which both took place in Rochester, US. They
presented posters: Marcin - Matrix product states for quantum metrology
and Radek "Multi-Spatial-Mode Optical Memory with Collective Raman
Scattering Inter-face".
Central European Quantum Information Processing Workshop
June 5-9, 2013
Two PhD students, Janek Kołodyński and Marcin Jarzyna took part in Central European Quantum Information Processing Workshop which was organized in Valtice, Czerch Republic. They gave talks on quantum metrology - Janek
"Efficient tools for quantum metrology with decoherence" and Marcin -
Matrix product states for quantum metrology.
Photons Beyond Qubits
April 8-10, 2013
Prof. Konrad Banaszek and Marcin Jarzyna have participated in Photons
Beyond Qubits workshop in Olomouc, Czech Republic. Prof. Banaszek gave a
talk Which-way experiment with an internal degree of freedom whereas Marcin Jarzyna presented a poster Matrix product states for quantum metrology.
Pre-print from diffusional decoherence studies
April 4, 2013
"How to measure diffusional decoherence in multimode Rubidum vapor memories?" The answer to this question, crucial for most atomic based multimode quantum memories can be found in pre-print on arXiv:1304.5396.
Quantum theory of reactive collisions for 1/r^n potentials
January 24, 2013
Scientists from our TEAM developed a general quantum theory for reactive collisions involving power-law potentials (-1/r^n) valid from the ultracold up to the high-temperature limit. Their quantum defect framework extends the conventional capture models to include the non-universal case when the short-range reaction probability P^{re} < 1 and relate their work to recent merged beam experiments on Penning ionization for collision energies below 0.1 meV [Henson et al, Science 338, 234(2012)].
Recent progress in experiments on optical memories - published
December 31, 2012
An open-access article "Generation and delayed retrieval of spatially multimode Raman scattering in warm rubidium vapors" by Radoslaw Chrapkiewicz and Wojciech Wasilewski has been published in Optics Express.
Open Access Articles
September 26, 2012
An open access to the following articles published by the members of our group: "Optimal phase estimation with arbitrary a priori knowledge" (Physical Review A), "Experimental Extraction of Secure Correlations from a Noisy Private State" (Physical Review Letters), "The elusive Heisenberg limit in quantum enhanced metrology" (Nature Communications) has been financed.
Conference on Quantum Communication, Measurement and Computing
July 30 - August 3, 2012
The major conference - Quantum Communication, Measurement and Computing (QCMC 2012) - organized since 1994, has been held in July in Vienna, Austria. The team of three PhD students Marcin Jarzyna, Janek Kołodynski and Mikołaj Lasota took part in this important biennial meeting and presented their individual posters: Janek - "The elusive Heisenberg limit in quantum enhanced metrology", Marcin - "Quantum interferometry with and without an external phase reference" and Mikołaj - "Security of practical quantum cryptography with heralded single photon sources".
The 23rd International Conference on Atomic Physics
July 23-27, 2012
Michał Krych has participated in the 23rd International Conference on Atomic Physics, which was held in the Ecole polytechnique, a high level graduate school close to Paris. Following the tradition of ICAP, the conference presented an outstanding programme of invited speakers covering the most recent subjects in the field of atomic physics. During the event Michał presented a scientific poster "Collisions of ultracold molecules - beyond the universal regime".
New article has appeared
July 13, 2012
An article "Eigenmode description of Raman scattering in atomic vapors in the presence of decoherence" by Jan Kołodyński, Jan Chwedeńczuk, and Wojciech Wasilewski has appeared in Physical Review A.
Central European Workshop on Quantum Optics
July 2-6, 2012
A group of researchers from our team set off to take part in a large quantum optics conference - Central European Workshop on Quantum Optics (CEWQO 2012) - this year organized in Sinaia, a mountain resort of Romania. The project leader prof. Konrad Banaszek has been invited to give a talk on the effect of dispersion cancellation via entanglement titled "Entanglement-sensitive effects in two-photon propagation". Janek Kolodynski, a 2nd year PhD student, contributed with a talk on our recent results in quantum metrology - "The elusive Heisenberg limit in quantum enhanced metrology", whereas 1st year PhD student, Marcin Jarzyna, presented a related poster "Quantum interferometry with and without external phase reference".
Advances in Foundations of Quantum Mechanics and Quantum Information with atoms and photons
May 20-27, 2012.
Rafal Demkowicz-Dobrzanski has delivered an invited talk entitled "Almost all decoherence models lead to shot noise scaling in quantum enhanced metrology" during the conference "Advances in Foundations of Quantum Mechanics and Quantum Information with atoms and photons".
New article has appeared
May 23, 2012
An article Quantum Theory of Reactive Collisions for 1/r^n Potentials by KrzysztofJachymski,Michał Krych, Zbigniew Idziaszek and Paul S. Julienne has appeared in Physical Review Letters.
Photons Beyond Qubits - Workshop on Quantum Information Processing
April 23-25, 2012
Prof. Konrad Banaszek and Mikołaj Lasota have participated in Photons Beyond Qubits - Workshop on Quantum Information Processing, which was held at the Faculty of Science in Palacky University in Olomouc. During the event they contributed with talks on recent results in quantum cryptography: Prof. Banaszek - "Experimental generation and characterisation of private states", Mikołaj - "Security of practical quantum cryptography with heralded single photon sources".
ProQuP 2012 workshop
April 2-3 2012
Jan Chwedenczuk participated in a ProQuP 2012 workshop held in Palaiseau in France. The meeting was devoted to quantum interferometry with ultra-cold atoms and quantum thermometry with quasi-condensates. During the workshop, Jan presented a talk entitled "Parameter estimation from the one-body density".
Quantum Information and Measurement
March 19-21, 2012.
Marcin Jarzyna and Janek Kolodynski took part in the OSA (Optical Society of America) Topical Meeting: Quantum Information and Measurement held during the conference Laser Optics Berlin in Germany.
International OSA Network of Students 11 - Paris 2012
February 22-25, 2012
Radoslaw Chrapkiewicz has participated in the conference International OSA Network of Students 11 - Paris 2012. The conference gathered PhD students and scientist from whole Europe. Radoslaw Chrapkiewicz presented his last results on the poster. He has got the award for the best poster presentation.
An International Workshop on Quantum Information (IWQI-2012)
February 20-26, 2012
An International Workshop on Quantum Information (IWQI-2012) was held during 20 -26 February, 2012 at the Harish-Chandra Research Institute (HRI), Allahabad, India. The leader of our TEAM - prof. Konrad Banaszek presented a talk entitled "Experimental security analysis of a four-photon private state".
New article has appeared
February 15, 2012
An article "Ultranarrow Faraday rotation filter at the Rb D1 line" by Joanna A. Zielińska, Federica A. Beduini, Nicolas Godbout, and Morgan W. Mitchell has appeared in Optics Letters.
AQUTE Winter School on Quantum Information Processing
February 6-10, 2012
Radoslaw Chrapkiewicz has participated in the Winter School on Quantum Information Processing organized by AQUTE in Obergurgl in Austria. During the school he presented the recent result on the subject of Holographic, multimode memory in rubidium vapours.
New article has appeared
January 27, 2012
An article "Quantum interferometry with and without an external phase reference" by Marcin Jarzyna and Rafał Demkowicz-Dobrzański has appeared in Physical Review A.
First NASA Quantum Future Technologies Conference
January 17-21, 2012.
Rafal Demkowicz-Dobrzanski has delivered an invited talk entitled "Theoretical tools for quantum enhanced metrology" (video) during the First NASA Quantum Future Technologies Conference showing novel tools for proving fundamental bounds on achievable precision in quantum enhanced metrology. Results are of high relevance for future implementations of quantum metrological protocols in gravitational wave detectors and atomic clocks.
Open Day of the Warsaw University's Department of Physics
November 26, 2011
In the main building of the department at 69 Hoża Street many presentations and lectures for the broad public have taken place. The TEAM program members, Janek Kolodynski and Marcin Jarzyna have actively taken part in the Science Cafe, where they have tried to convince the future and current students that Quantum Information is not only an interesting and surprising subject of contemporary Physics, but also its research's fruit are slowly starting to appear in our everyday lives.
fot. A. Sułkowska
Special seminar
September 19, 2011
On Monday September 19, 2011 we will have a honor to host Prof. Ian Walmsley (University of Oxford), who will give a talk on "Entang-bling: quantum correlations in diamond". 10:00 am, SSD lecture hall, Faculty of Physics, Hoża 69.
Our researchers at the International Symposium on Quantum Metrology in Toruń
September 17, 2011
The team of two PhD students: Mikołaj Lasota and Janek Kołodyński, and senior researcher Dr Rafal Demkowicz-Dobrzański took part in the International Symposium "Quantum Metrology with Photons and Atoms" in Toruń. Dr Demkowicz-Dobrzański was invited to give a talk on the subject of "Quantum enhanced interferometry", whereas both Janek and Mikołaj presented their individual posters.
MSc thesis defended
September 10, 2011
A MSc thesis entitled "Quantum states of light generated by Raman scattering in rubidium vapours" by project member Radosław Chrapkiewicz was
successfully defended on 10th September 2011. Click here to download the thesis (in Polish).
Strongly correlated Stokes and anti-Stokes scattering observed
August 10, 2011
On 10th August 2011 Radosław Chrapkiewicz and Wojciech Wasilewski reported first observation of the generation strongly correlated Stokes and anti-Stokes Raman scattering in hot Rubidium vapours
Lab renovation completed
July 31, 2011
On July 31, 2011 the renovation of our new Quantum Photonics Lab at Pasteura Street was completed. The
room was fully refurbished and equipped with an efficient AC system. We are now ready to install our equipment.
New article has appeared
June 28, 2011
An article "Phase estimation from atom position measurements" by J. Chwedenczuk, F. Piazza and A. Smerzi has appeared in the New Journal of Physics.
New article has appeared
June 28, 2011
An article "Mean field effects on the scattered atoms in condensate collisions" by P. Deuar, P. Zin, J. Chwedenczuk, and M. Trippenbach has appeared in THE EUROPEAN PHYSICAL JOURNAL D.
New article has appeared
June 20, 2011
An article "Bogoliubov dynamics of condensate collisions using the positive-P representation" by P. Deuar, J. Chwedenczuk, M. Trippenbach, and P. Zin has appeared in Phys. Rev. A.
Quantum cryptography is not picky
January 18, 2011
Our recent research on noisy photonic entangled states has been just published in Phys. Rev. Lett. We experimentally demonstrate secure quantum key generation using noisy 4-photon entangled states whose secure key contents exceeds distillable entanglement.
fot. G. Krzyżewski
MSc thesis defended
January 17, 2011
A MSc thesis entitled "Realistic phase estimation using squeezed states" by project member Marcin Jarzyna was successfully defended on the 17th of January 2011. Click here to download the thesis (in Polish).
11
10/2013
It is theoretically demonstrated that the recently reported quantum-noise-limited sensitivity of the squeezed-light-enhanced German-British gravitational wave detector GEO 600 is exceedingly close to the fundamental theoretical bound, given the present amount of optical loss. Furthermore, it is proven that the employed combination of a bright coherent state and a squeezed vacuum state is generally the optimum practical approach for phase estimation with high precision on absolute scales. [Demkowicz-Dobrzanski et al, Phys. Rev. A 88, 041802(R) (2013)]
