QIPC

Quantum computation speedup limits from quantum metrological precision bounds

Date: 
2015-06-17 - 2016-06-17
Author(s): 

Rafał Demkowicz-Dobrzański, Marcin Markiewicz

Reference: 

Phys. Rev. A 91, 062322 (2015) http://arxiv.org/abs/1412.6111

We propose a scheme for translating metrological precision bounds into lower bounds on query complexity of quantum search algorithms. Within the scheme the link between quadratic performance enhancement in idealized quantum metrological and quantum computing schemes becomes clear.

Incoherent on-off keying with classical and non-classical light

Date: 
2015-02-09
Author(s): 

Marcin Jarzyna, Piotr Kuszaj, Konrad Banaszek

Reference: 

Optics Express 23, 3170-3175 (2015), http://arxiv.org/abs/1410.4575

We analyze the performance of on-off keying (OOK) and its restricted version pulse position modulation (PPM) over a lossy narrowband optical channel under the constraint of a low average photon number, when direct detection is used at the output. An analytical approximation for the maximum PPM transmission rate is derived, quantifying the effects of photon statistics on the communication efficiency in terms of the g(2) second-order intensity correlation function of the light source. Enhancement attainable through the use of sub-Poissonian light is discussed.

Using Entanglement Against Noise in Quantum Metrology

Date: 
2014-12-19
Author(s): 

Rafal Demkowicz-Dobrzański, Lorenzo Maccone

Reference: 

Phys. Rev. Lett. 113, 250801 (2014) http://arxiv.org/abs/1407.2934

We analyze the role of entanglement among probes and with external ancillas in quantum metrology. In the absence of noise, it is known that unentangled sequential strategies can achieve the same Heisenberg scaling of entangled strategies and that external ancillas are useless.

Bayesian quantum frequency estimation in presence of collective dephasing

Date: 
2014-06-18 - 2014-10-31
Author(s): 

Katarzyna Macieszczak, Martin Fraas, Rafał Demkowicz-Dobrzański

Reference: 

New J. Phys. 16, 113002 (2014)

We advocate a Bayesian approach to optimal quantum frequency estimation—an important issue for future quantum enhanced atomic clock operation. The approach provides a clear insight into the interplay between decoherence and the extent of prior knowledge in determining the optimal interrogation times and optimal estimation strategies.

Symposium on Topological Quantum Information

Date: 
2016-05-25 - 2016-05-27
Registration deadline: 
2016-05-01 (All day)
Place: 
Athens, Greece

The 20th Symposium on Topological Quantum Information

Focus areas include, Topological insulators, superconductors and semimetals, Topological quantum liquids, Topological quantum computation, Classification of topological states and Topological states in cold atoms & materials.

List of speakers includes

J. H. Bardarson (MPI-PKS)
E. J. Bergholtz (Freie Universität Berlin)
I. F. Herbut (Simon Fraser University)
L. Hozoi (IFW Dresden)
D. Jennings (Imperial College London)
J. Knolle (University of Cambridge)
C. Mudry (Paul Scherrer Institute)
S. Rachel (TU Dresden)

Computer gamers solve quantum problems

Summary: 

More than 10,000 computer-game enthusiasts have helped physicists in Denmark to design better protocols for running quantum computers.

More than 10,000 computer-game enthusiasts have helped physicists in Denmark to design better protocols for running quantum computers.

13th Central European Quantum Information Processing Workshop (CEQIP)

Date: 
2016-06-16 - 2016-06-19
Registration deadline: 
2016-05-05 (All day)
Place: 
Valtice, Czech Republic

Dear friend,

looking for new scientific ideas and a (qu)bit of research-oriented
entertainment at the beginning of this summer? Then you know that
the beginning of spring is the right time to visit this website http://ceqip.eu/

You are welcome to register and submit your research to
a traditional (already 13th) quantum information meeting

CENTRAL EUROPEAN QUANTUM INFORMATION PROCESSING WORKSHOP.

Quantum Information added to Physical Review A’s statement of coverage

Summary: 

Physical Review A has recently changed its formal statement of coverage to explicitly include Quantum Information.

Physical Review A has recently changed its formal statement of coverage to explicitly include Quantum Information.

Annales Henri Poincare opens a Section in Quantum Information Theory

Summary: 

One of the most prestigious journals on mathematical and theoretical physics, “Annales Henri Poincaré” (AHP), has opened a Section in Quantum Information Theory.

One of the most prestigious journals on mathematical and theoretical physics, “Annales Henri Poincaré” (AHP), has opened a Section in Quantum Information Theory.

Summerschool "Nanotechnology meets Quantum Information"

Date: 
2016-07-11 - 2016-07-14
Registration deadline: 
2016-04-30 (All day)
Place: 
Donostia-San Sebastián
Website: 

nanoqi.dipc.org

The school "Nanotechnology meets Quantum Information (NanoQI)" aims to provide a broad overview of different implementations of quantum information processing and quantum simulation enabled by recent progress in nanotechnologies.

Syndicate content