The Quantum Rio Workshop strikes back!

The time has come. Again. Next week the quantum information community from Rio and surrounds will gather at CBPF to show what we’ve been up to this year, what we are planning for 2018. It will be an informal, relaxed, kind of family meeting. The idea of the workshop is to foster more interaction and collaboration among the quantum information/quantum optics researchers in the area.

Information about the event can be found at

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

See you there!


New article: Quantum Algorithm for Simulating the Wave Equation

Quantum Information Group @ CBPF

Title: Quantum Algorithm for Simulating the Wave Equation

Authors: Pedro C.S. Costa (CBPF), Stephen Jordan (NIST/Maryland), Aaron Ostrander (Maryland)


Abstract: We present a quantum algorithm for simulating the wave equation under Dirichlet and Neumann boundary conditions. The algorithm uses Hamiltonian simulation and quantum linear system algorithms as subroutines. It relies on factorizations of discretized Laplacian operators to allow for improved scaling in truncation errors and improved scaling for state preparation relative to general purpose linear differential equation algorithms. We also consider using Hamiltonian simulation for Klein-Gordon equations and Maxwell’s equations.

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New article: Reversing the thermodynamic arrow of time using quantum correlations

Quantum Information Group @ CBPF

Title: Reversing the thermodynamic arrow of time using quantum correlations

Authors: Kaonan Micadei, John P. S. Peterson, Alexandre M. Souza, Roberto S. Sarthour, Ivan S. Oliveira, Gabriel T. Landi, Tiago B. Batalhão, Roberto M. Serra, Eric Lutz


Abstract: The second law permits the prediction of the direction of natural processes, thus defining a thermodynamic arrow of time. However, standard thermodynamics presupposes the absence of initial correlations between interacting systems. We here experimentally demonstrate the reversal of the arrow of time for two initially quantum correlated spins-1/2, prepared in local thermal states at different temperatures, employing a Nuclear Magnetic Resonance setup. We observe a spontaneous heat flow from the cold to the hot system. This process is enabled by a trade off between correlations and entropy that we quantify with information-theoretical quantities.

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QM Talks@CBPF: Alexandre B. Tacla — 13.11, 16h00

Quantum Information Group @ CBPF

Our next talk in the series QM Talks@CBPF will be delivered by Alexandre B. Tacla (Glasgow). Alexandre has many interests, and a broad knowledge. In this talk he will tell us about his recent results on how to deal with complex many-body systems in an efficient way.

Note that this week, due to the holiday celebrating the Proclamation of the Republic in Brazil on Wednesday, the talk will be on Monday. See the full info below, and be sure to not miss this talk!

Title: Particle-correlated states: A non-perturbative treatment beyond mean field

Speaker: Alexandre B. Tacla (Glasgow)

Coordinates: room 601C, CBPF. 13.11 (Monday), 16h00

Abstract: Many useful properties of dilute Bose gases at ultralow temperatures are predicted precisely by the (mean-field) product-state Ansatz, in which all particles are in the same single-particle state. However, in situations where particle-particle correlations become important, this technique fails and more sophisticated…

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QM Talks@CBPF: Marcelo F. Santos — 08.11, 16h00

Quantum Information Group @ CBPF

This week we have the pleasure to receive Marcelo F. Santos (UFRJ) as a speaker in our series QM Talks@CBPF. Marcelo and co-authors have recently put in the arXiv an intriguing paper: Photonic Counterparts of Cooper Pairs. This article, already accepted for publication in Physical Review Letters, attracted quite some attention (see here the Nature News feature on the article) for proposing that photons can interact inside a medium in a way very similar to that of electrons in a superconducting material, forming the so-called Cooper pairs. Got interested?! Then do not miss Marcelo’s talk. The info follows:

Title: Photonic Cooper pairs

Speaker: Marcelo F. Santos (UFRJ)

Coordinates: room 601C, CBPF. 08.11, 16h00

Abstract: Photons are the elementary particles of light. Contrary to most particles, photons do not interact directly with each other in vacuum. However, when propagating in a material, e.g. water, photon pairs may interact through the medium…

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QM Talks@CBPF: Thiago Guerreiro — 01.11, 16h00

Quantum Information Group @ CBPF

Following with our series of seminars QM Talks@CBPF, the next talk will be given by Thiago Guerreiro (PUC-RJ). Thiago has just returned to Brazil after postdoc and PhD in the group of Nicolas Gisin. In this “welcome back” talk, Thiago will tell us about his recent results and also about his research plans. Be sure to be there!

Title: Table-top high-energy quantum physics

Speaker: Thiago Gurreiro (PUC-RJ)

Coordinates: room 601C, CBPF. 01.11, 16h00

Abstract: Often in history, important measurements and discoveries were preceded by long periods of technical development. Today, fundamental physics may be at the edge of a new exciting age which will exploit the development of so-called quantum technologies. In this talk I will discuss examples of how precise control over quantum matter can lead to new developments in fundamental physics, from gravitational waves to the search for new particles and interactions of nature.

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COTEO@CBPF: Giuseppe Di Molfetta — 25.10, 14h30

Quantum Information Group @ CBPF

From this Friday (20.10) up to the end of the month we have the pleasure to receive Giuseppe Di Molfeta at CBPF. Giuseppe has many contributions to the topic of quantum walks. More specifically he employs quantum walks to simulate all sort of systems: from neutrino oscillations and Dirac equation, all the way up to gravity! The latter is the subject of the talk he will deliver in the Theory Seminar. See the details below, and be sure to be there!

Title: Quantum walking in curved spacetime

Speaker: Giuseppe Di Molfetta (Université Aix-Marseille )

Coordinates: seminar room 6th floor, CBPF. 25.10, 14h30

Abstract:In the framework of Quantum Simulation, a crucial topic for the exploration of physical situations where experiments are currently hard or impossible to setup (e.g. quantum gravity), Quantum Walks (QW) are increasingly recognized as prominent models. A discrete-time QW is essentially a unitary operator driving the evolution of…

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