15th CEQIP workshop, June 13-16 2018, Smolenice, Slovakia

Posted on 5th June 2018 in News

Our good friend Mario Ziman is co organizing the CEQIP meeting. Our group is going to be represented by Antonio Rosado.

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Seminario de Isaac Pérez

Posted on 9th May 2018 in News, Reunion

A toda la comunidad GIOC les hacemos una cordial invitación al seminario especial que impartirá Isaac Pérez Castillo este viernes 11 de mayo a las 13:00 en la Sala de Eméritos del IFUNAM:

Title: Out-of-equilibrium phase transitions induced by Floquet
resonances in a periodically quench-driven XY spin chain

Abstract: We consider the dynamics of an XY spin chain subjected to an
external transverse field which is periodically quenched between two
values. By deriving an exact expression for this out-of-equilibrium
protocol’s Floquet Hamiltonian, we show how the parameter space of the
system is characterized by alternations between local and non-local
regions, corresponding respectively to the absence and presence of
Floquet resonances. The boundary lines between regions are  obtained
analytically from avoided crossings in the Floquet quasi-energies and
are observable as phase transitions in the synchronized state. The
transient behaviour of dynamical averages of local observables similarly
undergoes a transition, showing either a rapid convergence towards the
synchronized state in the local regime, or a rather slow one exhibiting
persistent oscillations in the non-local regime.

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Inicia un nuevo proyecto

Posted on 13th April 2018 in News

Al grupo le fue otorgado el proyecto de Ciencia Básica “Manifestaciones del enlazamiento y la decoherencia cuántica”. Este tendrá una duración de tres años.

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Curso de Informacion cuantica relativista y metrologia

Posted on 6th April 2018 in News, Reunion

La semana que viene tendremos un curso de Información y metrología cuántica relativista. Será impartido por Ivette Fuentes, en la sala Sandoval Vallarta el el lunes 9, miercoles 11 y viernes 13 de 16:00 a 17:30.

 

Notas del curso:

RQI_notes_part1

RQI_notes_part2

RQI_notes_part3

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Dos nuevos articulos en sitemas complejos!

Posted on 6th March 2018 in News

Acabamos de enviar dos articulos de sistemas complejos. Uno, ya aceptado, de la estabilidad del TSP (traveling salesman problem) [https://arxiv.org/abs/1708.06945]. El otro, de la evolución del lenguaje a diferentes escalas [https://arxiv.org/abs/1802.07258].

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Gira de David Davalos

Posted on 16th February 2018 in News

David Dávalos viajara a Europa a visitar al grupo de Mario Ziman en Bratislava, el de Juan Diego Urbina en Regensburg y al grupo de relatividad cuántica de la Universidad de Viena.

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Esteban Martinez en Grup d’Informació Quàntica

Posted on 24th November 2017 in News

Esteban Martinez inicia su estancia en el Grup d’Informació Quàntica de la Universidad Autónoma de Barcelona a partir de Octubre de 2017. Mucho exito!

http://grupsderecerca.uab.cat/giq/

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Curso corto de cómputo cuántico

Posted on 13th October 2017 in News

Estimados todos, les compartimos la información de un próximo curso de cómputo cuántico que será impartido en el IFUNAM por el profesor Ernesto F. Galvão

Título: Ingredients for universal quantum computation
Profesor: Prof. Ernesto F. Galvão
Instituto de Física, Universidade Federal Fluminense (Niterói, Brazil)
Lugar: Salón de Eméritos, Instituto de Física, UNAM
Fechas: 25-27 Octubre 2017
Hora: 11:00am

Resumen:

I will start by reviewing the main ingredients for a universal
quantum computer in the circuit model: universal sets of gates, the
importance of restricting input states and output measurements, etc
[1]. Then I will review the basics of some alternative models of
quantum computation, such as measurement-based quantum computation [2]
and models which use linear optics (e.g. the KLM scheme [3] and Boson
Sampling [4]).
By mixing and matching the various ingredients, we will identify
different combinations which yield interesting regimes in terms of
computational power: full universal quantum computation, simulable
quantum dynamics, or an intermediate or incomparable computational
power (e.g. IQP [5], Boson Sampling [4], DQC-1 [6]). This line of
research helps identify what’s essential and what’s acessory for the
quantum computational advantage, with practical implications for
experimental implementations. I will give special attention to
experiments I took part in [7] using specialized linear optical
computers to solve the Boson Sampling problem [4], which I will
describe in some detail.

References:

[1] Michael A. Nielsen and Isaac L. Chuang, Quantum Computation and
Quantum Information (Cambridge University Press, 2000).
[2] R. Raussendorf and H. J. Briegel, Phys. Rev. Lett. 86, 5188 (2001).
[3] E. Knill, R. Laflamme and G. J. Milburn, Nature 409, 46-52 (2001).
[4] S. Aaronson and A. Arkhipov. The Computational Complexity of
Linear Optics, Theory of Computing 4:143-252 (2013).
[5] M. J. Bremner, R. Jozsa and Dan J. Shepherd, Proc. R. Soc. A vol.
467 no. 2126 459-472 (2011).
[6] E. Knill and R. Laflamme, Phys. Rev. Lett. 81, 5672 (1998).
[7] M. Bentivegna et al., Experimental scattershot boson sampling.
Science Advances 1 (3), e1400255 (2015); [16] N. Spagnolo et al.,
Experimental validation of photonic boson sampling. Nature Photonics
8, 615–620 (2014).

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Nuevo paper

Posted on 5th September 2017 in News

Quantum non-Markovianity and localization
David Davalos, Carlos Pineda

We study the behavior of non-Markovianity with respect to the localization of the initial environmental state. The “amount” of non-Markovianity is measured using divisibility and distinguishability as indicators, employing several schemes to construct the measures. The system used is a qubit coupled to an environment modeled by an Ising spin chain kicked by ultra-short pulses of a magnetic field. In the integrable regime, non-Markovianity and localization do not have a simple relation, but as the chaotic regime is approached, simple relations emerge, which we explore in detail. We also study the non-Markovianity measures in the space of the parameters of the spin coherent states and point out that the pattern that appears is robust under the choice of the interaction Hamiltonian but does not have a KAM-like phase-space structure.
https://arxiv.org/abs/1708.06208

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ELAF

Posted on 1st August 2017 in News

Se lleva a cabo una de las escuelas mas importante de latinoamérica: la ELAF. Esta vez, el tema son las correlaciones cuánticas. Encontrarán toda la información en su sitio web https://www.elaf2017.org/ .

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