Beer and Quantum Physics

Now that I have your attention:

Come share your thoughts about EPR and IPAs!

Pint of Science 2018:  O estranho mundo quântico e o futuro da informática

When:  May 16 2018 – 19:30

Where: Teto Solar, Teto Solar Rua Paulo Barreto, 110A – Botafogo,
Rio de Janeiro 22280-010


Talk @UFRJ, Liliana Sanz, Monday 14/05, 15H30

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

See the details of the talk below:

MONDAY, May 14th, at 15H30
in room 343 (3rd floor of block A of the Technology Center building)

“Dinâmica quântica em pontos quânticos carregados”
Liliana Sanz(UFU)

Discutiremos propostas teóricas, desenvolvidas no Grupo de Óptica e Informação Quântica no INFIS-UFU, considerando um sistema físico que se destaca pela sua versatilidade: os pontos quânticos carregados. Em estes sistemas, através de eletrodos, é possível controlar a taxa de tunelamento coerente de elétrons entre pontos, além do processo de inicialização usando reservatórios de partículas. Dependendo da construção, elétrons podem interagir via Coulomb. Discutiremos resultados mais antigos [Annals of Physics 356, 244 (2015)], onde demonstramos a criação dinâmica de estados maximamente emaranhados neste cenário. Após esta introdução, discutimos os efeitos do acoplamento dos elétrons nesses pontos carregados com modos bosônicos. Nesse contexto, demonstramos que a combinação entre tunelamento e o interação elétron-bóson pode ser vista como um acoplamento efetivo entre elétrons inicialmente não interagentes, viabilizando novamente a formação de estados emaranhados [ArXiv:1804.01123]. Finalmente, apresentaremos um formalismo para o tratamento destes pontos como sistemas abertos [PRA 96, 052110 (2017)], com uma aplicação particular em detecção de assinaturas da formação de um dubleto de Autler-Townes nas medidas de fotocorrente [ArXiv:1805.01076].


You can incorporate our calendar to your Google Calendar and have information about all the confirmed seminars using this link.

Talk @UFF: Gabriel Bié Alves, Friday May 11th, 11.00

The group seminar at UFF this week will be given by Gabriel Bié Alves (UFF), who’ll be talking on “Condições para oscilação paramétrica ótica com um bombeio estruturado” next Friday, May 11th, at 11.00 in room A5-01. All are welcome! Please find an abstract below. Read the rest of this entry »

Charles Bennett @UFRJ!

Colloquium IF/UFRJ


11am Bloco A – Sala 343


Charles Bennett

IBM Research

Is there such a thing as private information?

One of the original motivations for quantum information theory was the use of quantum effects to protect the privacy of classical communications.  Yet the new theory, which has grown to elegantly encompass all of classical informatics, has undermined the very notion of classical private information, by showing that it sits on a slippery slope between quantum information and public information.  Classical privacy survives only as a useful approximation, since in principle any memory so well shielded that it can hold classical data without the environment finding out can also hold superpositions of the classical values, thereby serving as a quantum memory.  To recover a sharp notion of classical privacy it suffices to consider scenarios in which some information escapes to a place beyond the reach of one’s adversaries.  At a more practical level I argue that device independent (DI) randomness generation is inferior to crowd-sourced and DIY (do-it-youself) methods, and DI methods of quantum key distribution are inferior to measurement-device independent (MD-QKD) methods.

Talk @UFRJ, Sebastião Pádua, Monday 07/05, 15H30

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

See the details of the talk below:

MONDAY, May 7th, at 15H30
at the LADIF’S auditorium (4th floor of block A of the Technology Center building)

“Automated quantum operations in photonic qutrits”
Sebastião Pádua (UFMG)

We develop an experimental optical setup capable of implementing a class of quantum operations in photonics qutrit states in transverse Gaussian paths variables. In order to implement a projection operation is necessary to be able, in principle, to transform an initial state that can be an one component state in a superposition of the others base states. The system that implements the operations needs to transform one photonic path state in a state of D paths at the apparatus exit. Such transformation is difficult to be realized for slit states. We present an experimental implementation of projection and permutation operations using a photonic qutrit encoded in transverse Gaussian path states. Such experimental setup allows to obtain a qutrit state at the apparatus exit making them useful for a sequential quantum operation. The present operations are implemented exploring the diffraction of a Gaussian beam by a SLM due to a periodic phase modulation in it. We identify one set of diffraction phase grating for each operation realized, so the experiment is automated in the sense the operations are changed just by changing the SLM phase grating by a computer.


You can incorporate our calendar to your Google Calendar and have information about all the confirmed seminars using this link.

Minicourse on Quantum Entanglement: From Quantum Information to Many-Body Physics and Beyond (20-24/08 @ ICTP/SAIFR-UNESP, São Paulo)

From 20 to 24 of August, 2018, at ICTP/SAIFR-UNESP, in São Paulo.

Professor Fernando Brandão (CalTech) and Dr. Burak Sahinoglu (Caltech, USA) will deliver a one-week mini-course on quantum many-body entanglement.

Mini-course on quantum entanglement and many-body physics

The course will be open (no registration fee) to post-graduate students (or postdocs) working on quantum information, or connected areas (e.g., condensed matter physics, statistical mechanics, and high energy physics).

New paper & talk @UFF: Witnessing genuine multi-photon indistinguishability

Daniel Brod and I (Ernesto Galvão) have recently posted a new preprint on the arxiv, the latest result of our long-standing collaboration with the experimental group of Fabio Sciarrino at Sapienza University of Rome. I’ll be giving a talk about it next Friday, April 20th, at 11.00 in room A5-01, come if you can!

The paper describes a way to test whether a set of single-photon sources is producing a state of n genuinely indistinguishable photons, as opposed to some convex combination of states in which effectively less than n photons interfere. As it turns out, this question can be motivated by a simple logic problem, as I explain below. Then I briefly describe how the Rome lab experimentally tested our idea. Read the rest of this entry »