Talk @UFF, A. Bramati (Lab. Kastler Brossel, Paris), Friday May 24th, 11.00

This week’s talk at the Infoptics group @UFF will be given by our visitor from Paris, A. Bramati (Laboratoire Kastler Brossel, UPMC-Sorbonne 
Universités). His talk’s title is “Quantum fluids of light and nano-photonics at LKB”, and it’s scheduled for next Friday, May 24th, at 11.00 in room A5-01. All are welcome! For an abstract, please see below.

Data: Sexta-Feira 24/05/2019, Sala A5-01, 11 am.

Speaker: A. Bramati (Laboratoire Kastler Brossel, UPMC-Sorbonne 
Universités)

Title: Quantum fluids of light and nano-photonics at LKB

Abstract: In this talk I will present an overview of the recent experiments performed in our group. The first part of the talk will be devoted to the so called quantum fluids of light [1], a wide family of systems where an effective photon-photon interaction can be engineered, resulting in a  hydrodynamical-like behavior. In particular I will focus on microcavity polaritons and atomic vapors. In polaritons, I will show how the development of flexible all-optical methods to inject a controlled orbital angular momentum in such systems results in the observation of
patterns of quantized vortices [2, 3]. These results open the way to the study of Abrikosov-like physics and new vortex collective phenomena. In Rubidium atomic vapors, I will present very recent experiments demonstrating the superfluid behavior in these media.

The second part of the talk will be devoted to our recent results on 
efficient room temperature single photon emitters based on core/shell colloidal semiconductor nanocrystals. By using asymmetric core/shell nanoparticles (dots-in-rods), blinking effects, multi-excitonic emission and 
polarization of the emitted photons can be simultaneously controlled by tuning the shell dimensions [4] allowing to achieve “state of the art” blinking-free sources of polarized single photons on-demand. Finally, I will discuss the different strategies we are pursuing to
develop hybrid photonic devices by coupling single nanocrystals with  various photonic structures like optical nanofibers, deep parabolic mirrors [5], liquid crystals [6] and semiconductor nanowires [7].

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Talk @UFF, Ernesto Galvão, Friday May 17th, 11.00

I will be giving this week’s talk at our group at UFF. Please come to room A5-01, next Friday May 17th at 11.00 to hear me talk about “Dimension and coherence witnesses from SWAP tests”. For an abstract, please see below.


Room A5-01. Friday, May 17th, 2019, 11.00.

Speaker: Ernesto F. Galvão (UFF)

Title: Dimension and coherence witnesses from SWAP tests

Abstract: The SWAP test is a simple quantum circuit that projects onto the symmetric subspace of two quantum systems. When applied to two separable states, it results in a direct estimation of the two-state overlap Tr(rho sigma). Using many such tests, we can gather information about many pairwise overlaps of N states. I’ll show how this relational information can be used to witness quantum coherence, i.e. guarantee that the states are not diagonal in any single basis. I’ll also show how these tests can be used as a Hilbert space dimension witness. Finally, I’ll briefly describe how to implement these tests using linear optics.


Talk @UFRJ, Caio Lewenkopf, Monday 13/05, 15H30

The Quantum Optics and Information Group (UFRJ) is proud to announce next week’s seminar, which will be given by Caio Lewenkopf (UFF). We invite all to come!

See the details of the talk below:

MONDAY, May 13th, at 15H30
in room 343 (3rd floor of block A of the Technology Center building)

“​Produção de entropia no transporte eletrônico através de sistemas nanoscópicos fortemente acoplados”
Caio Lewenkopf (UFF)

Abstract:
Apresentarei nesta palestra uma abordagem descrever propriedades termodinâmicas de sistemas quânticos na escala nanoscópica. Uma das dificuldades principais deste tipo de estudo e que tais sistemas não possuem um número grande de constituintes e, portanto, não satisfazem uma das premissas fundamentais das teorias microscópicas que descrevem relações termodinâmicas. Outro problema central está associado à dificuldade de estabelecer uma distinção entre o “sistema”, o “banho” e suas “interfaces” em objetos muito diminutos. Nesta palestra apresentarei uma teoria para a produção de entropia causada pelo transporte eletrônico em sistemas mesoscópicos (com comprimentos muito menores que a escala de coerência quântica) fortemente acoplados a reservatórios em equilíbrio térmico e químico. Mostrarei que, usando a abordagem de Landauer-Büttiker, é possível construir um formalismo que não necessita introduzir partições [1], evitando uma distinção entre sistema e banho. Discutirei como o formalismo proposto recupera os resultados de teorias termoelétricas padrão para processos estacionários fora do equilíbrio e como estendê-lo para sistemas tempo-dependentes, discussão essencial para entender o funcionamento de motores quânticos.

[1] Anton Bruch, Caio Lewenkopf, Felix von Oppen, Physical Review Letters 120, 107701 (2018)
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Talk @UFF, Braian da Silva, May 10th, 11:00

This week’s talk at the Infoptics group (UFF) will be given by Braian Pinheiro da Silva (UFF), next Friday, May 10th, in room A5-01 at 11:00. His talk is titled “Self imaging from fractional Gouy phases in paraxial optics”, all are welcome! Please see below for an abstract.


Data: Sexta-Feira 10/05/2019, Sala A5-01, 11 am.

Palestrante: Braian Pinheiro Da Silva (UFF)

Title: Self imaging from fractional Gouy phases in paraxial optics.

Abstract: We investigate self-imaging structures composed by paraxial 
mode superpositions in optics. When different mode orders are combined, the resulting  pattern is not preserved under free propagation and gets transformed as a result of non  synchronized Gouy phases. However, it is possible to build self imaging structures in which the Gouy phases synchronize at specific longitudinal positions, recovering the initial pattern.


Talk @UFRJ, Adrian Budini, Monday 06/05, 15H30

The Quantum Optics and Information Group (UFRJ) is proud to announce next week’s seminar, which will be given by Adrian Budini (Instituto Balseiro). We invite all to come!

See the details of the talk below:

MONDAY, May 6th, at 15H30
in room 343 (3rd floor of block A of the Technology Center building)

“Quantum non-Markovianity from Past-Future correlations”
Adrian Budini (Instituto Balseiro)

Abstract:
Diverse quantum non-Markov definitions are constructed over the basis of different quantum information measures, which in turn rely on the system density matrix evolution. Optical arrangements provide a natural basis for their experimental implementation [F. F. Fanchini, et. al., PRL 112, 210402 (2014); N. K. Bernardes, et. al., Sci. Rep. 5, 17520 (2015)]. Here, an alternative approach to quantum non-Markovianty is presented [Budini, PRL 121, 240401 (2018)]. In contrast to previous approaches, its definition relies on three consecutive quantum measurements performed over the system of interest and post-selection. Consistence with classical non-Markovianity and Born-Markov approximation are achieved.
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You can incorporate our calendar to your Google Calendar and be informed about all the confirmed seminars using this link.


Defesa de mestrado (HOJE): Isadora B. L. Veeren

Quantum Information Group @ CBPF

Candidata: Isadora Barbosa Lima Veeren,

Título da dissertação: Entropic uncertainty relations and classicality

Coordenadas: 30 de Abril às 16h. CBPF, auditório do sexto andar.

Banca: Fernando de Melo (CBPF), Bárbara Amaral (UFSJ*), Daniel Schneider Tasca (UFF), Ivan de Oliveira (CBPF) e Roberto Sarthour (CBPF).

Estão todxs convidadxs!

*não poderá participar.

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Talk @UFRJ, Mucio Continentino, Monday 29/04, 15H30

The Quantum Optics and Information Group (UFRJ) is proud to announce next week’s seminar, which will be given by Mucio Continentino (CBPF). We invite all to come!

See the details of the talk below:

MONDAY, April 29th, at 15H30
in room 343 (3rd floor of block A of the Technology Center building)

“Transições de Fase Quânticas em Matéria Condensada”
Mucio Continentino (CBPF)

Abstract:
Transições de fase quânticas ocorrem a temperatura nula. Nelas, devido ao principio da incerteza as flutuações espaciais e temporais estão indissoluvelmente acopladas. Seu interesse não é exclusivamente acadêmico pois em temperaturas suficientemente baixas podemos observar os efeitos de um ponto critico quântico. Neste seminário discutiremos algumas características das transições de fase quânticas e como elas podem ser estudadas experimentalmente em sistemas de matéria condensada.
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You can incorporate our calendar to your Google Calendar and be informed about all the confirmed seminars using this link.