New article: Vestiges of quantum oscillations in the open evolution of semiclassical states

Quantum Information Group @ CBPF

Title: Vestiges of quantum oscillations in the open evolution of semiclassical states

Author: Alfredo M. Ozorio de Almeida (qig@CBPF)


Abstract: A single wave component of a quantum particle can in principle be detected by the way that it interferes with itself, that is, through the local wave function correlation. The interpretation as the expectation of a local translation operator allows this measure of quantum wavyness to be followed through the process of decoherence in open quantum systems. This is here assumed to be Markovian, determined by Lindblad operators that are linear in position and momentum. The limitation of small averaging windows and even smaller correlation lengths simplifies the semiclassical theory for the evolving local correlation. Its spectrum has a peak for each classical momentum, subjected to Gaussian broadening with decoherence. These spectral lines can be clearly resolved even after the Wigner function has become positive: The correlations located…

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QM Talks@CBPF: Alex Bouvrie — 29.03, 16h00

Quantum Information Group @ CBPF

We resume our series of seminars with a talk by Alex Bouvrie, a postdoc here in the qig@cbpf. Indeed, Alex has just being awarded a new postdoc fellowship (PCI), which will allow him to stay a little longer with us. Luckly for us!

This time he’ll tell us about his latest results on composite fermions, and how the entanglement between them explains some features of experiments producing  Bose-Einstein condensates with fermions… got confused? Check out the details of his talk below,  and see you there!

Title: Quantum information in ultracold interacting Fermi gases

Speaker: Alex Bouvrie (CBPF)

Coordinates: room 601D, CBPF. 29.03, 16h00

Abstract: Recently the quantum information group of the CBPF showed that the application of the composite bosons theory [1] to ultracold  interacting Fermi gases is remarkable [2,3]. The effects of the underlying fermionic structure of composite bosons (molecules made from two fermions) formed in two-component Fermi gases…

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Paraty VI: Registration is open!

The time has come… again. The sixth edition of the Quantum Information School and Workshop is accepting applications.

In this edition we will be celebrating 10 years from the first “Quantum Paraty”. Ten years have passed but the relaxed atmosphere — great science, long lunch breaks, friendly people, a boat trip instead of the boring usual conference dinner, and Paraty itself –, that build up the reputation of Paraty as the coolest quantum information conference in the world, continue as our commandment. Ask people about it and register! All the info and registration form can be found in the conference webpage

See you in Paraty!

Open postdoc positions

Quantum Information Group @ CBPF

The Brazilian Center for Research in Physics (CBPF), a research unit of the Ministry of Science, Technology, Innovations and Communications (MCTIC), has openings for 13 postdoctoral scholar positions in various research topics. The topics include quantum information, both theory and experiment.

Interested candidates can find information about the call at

Contact us if you are willing to join our quantum information group as postdoc!

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Quantum Rio Workshop, Dec. 7/8th

Next week, on December 7th and 8th, in CBPF (at the 6th floor auditorium), we’ll have our first Quantum Rio Workshop, an informal gathering of the quantum information community in and around Rio, organized by Malena Hor-Meyll (UFRJ), Roberto Sarthour (CBPF) and Ernesto Galvão (UFF).

The idea of the workshop is to foster more interaction and collaboration among the quantum information/quantum optics researchers in the area. We’ve allocated half-hour talk slots to some of the group leaders, complemented by posters and coffee during the talk breaks, mostly by students (please encourage them to contribute!). The workshop will be financed by workshop fees (paid only by professors).

Please find the schedule below:

Wednesday, Dec. 7th:
9:00-09:30 Luiz Davidovich
9:30-10:00 Fernando Melo
10:00-10:30 coffee
10:30-11:00 Gabriel Aguilar
11:00-11:30 Alexandre Souza
11:30-12:00 Ernesto Galvão
12:00-14:00 lunch
14:00-14:30 José Augusto Huguenin/Alexandre Schmidt
14:30-15:00 Mohammad Rajabpour
15:00-16:00 coffee/posters
16:30-17:00 Marcelo França
17:00-17:30 Leandro Aolita
Thursday, Dec. 8th
9:00-09:30 Antonio Zelaquett Khoury
09:30-10:00 Itzhak Roditi
10:00-10:30 coffee
10:30-11:00 Fabricio Toscano
11:00-11:30 Daniel Jonathan/Thiago Oliveira
11:30-12:00 Daniel Tasca
12:00-14:00 lunch
14:00-14:30 Steve Walborn
14:30-15:00 Alfredo Osório
15:00-15:30 Eric Cavalcanti
15:30-16:30 coffee+posters

Please get in touch if you’re planning on attending (emailing Malena, Ernesto or Roberto), so that we can leave a participant list at the reception of CBPF, which is necessary for security purposes.

The quantum information community in Rio is quite large, and there are already many collaborations going on among the different groups. We hope this will be the first of many workshops that’ll help us make the most out of our rich human resources in the region. See you there!

Talk @UFF, Yelena Guryanova, Thurs. Dec. 1st, 11.00

This week our group seminar at UFF will happen exceptionally on Thursday, Dec. 1st, at 11.00, in room A5-01. This time round we have the visit of Yelena Guryanova (IQOQI- Institute for Quantum Optics and Quantum Information, Vienna), who’ll give a talk entitled: “Thermodynamics of quantum systems with multiple conserved quantities”. All are welcome to attend! Please find the abstract below. Read the rest of this entry »

QM Talks@CBPF: Yelena Guryanova — 30.11, 16h00

Quantum Information Group @ CBPF

Title: Thermodynamics of quantum systems with multiple conserved quantities

Speaker: Yelena Guryanova (IQOQI- Institute for Quantum Optics and Quantum Information)

Coordinates: room 601D, CBPF. 30.11, 16h00

Abstract: We consider a generalisation of thermodynamics that deals with multiple conserved quantities at the level of individual quantum systems. Each conserved quantity, which, importantly, need not commute with the rest, can be extracted and stored in its own battery. Unlike in standard thermodynamics, where the second law places a constraint on how much of the conserved quantity (energy) that can be extracted, here, on the contrary, there is no limit on how much of any individual conserved quantity that can be extracted. However, other conserved quantities must be supplied, and the second law constrains the combination of extractable quantities and the trade-offs between them which are allowed. We present explicit protocols which allow us to perform arbitrarily good trade-offs and extract arbitrarily good…

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