# Talk @UFF, Antonio Zelaquett Khoury, Friday Oct. 20th, 11.00

**Posted:**October 19, 2017

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This Friday, October 20th, at 11.00 in room A5-01 we’ll have our next group seminar at the Infoptics group (UFF). This week our own Antonio Zelaquett Khoury will talk on “Orbital angular momentum mixing in parametric amplification and oscillation”. All are welcome! Please see below for an abstract. Read the rest of this entry »

# Talk @UFRJ, Gabriel Aguilar (UFRJ), Monday 23/10, 15H30

**Posted:**October 18, 2017

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

See the *details* of the talk below:

MONDAY, **October 23th**, at **15H30**

in room **343** (3rd floor of block A of the Technology Center building)

**“Entanglement between hundreds of macroscopic ensembles”**

**Gabriel Aguilar (UFRJ)**

*Abstract:*

There are both fundamental and practical motivations for studying whether quantum entanglement can exist in macroscopic systems. However, multiparty entanglement is generally fragile and difficult to quantify. Dicke states are multiparty entangled states where a single excitation is delocalized over many systems. Building on previous work on quantum memories for photons, we create a Dicke state in a solid by storing a single photon in a crystal that contains many large atomic ensembles with distinct resonance frequencies. The photon is re-emitted at a well-defined time due to an interference effect analogous to multi-slit diffraction. We derive a lower bound for the number of entangled ensembles based on the contrast of the interference and the single-photon character of the input, and we experimentally demonstrate entanglement between over two hundred ensembles, each containing a billion atoms. We also illustrate the fact that each individual ensemble contains further entanglement.

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

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

**Posted:**October 16, 2017

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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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# Talk @UFRJ, Frederico Brito (USP), Monday 16/10, 15H30

**Posted:**October 15, 2017

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The *Quantum Optics and Information Group (UFRJ)* is proud to announce tomorrow’s seminar, which will be given by Frederico Brito (USP). We invite all to come!

See the *details* of the talk below:

MONDAY, **October 16th**, at **15H30**

in room **343** (3rd floor of block A of the Technology Center building)

**“Quantum work by a single photon”**

**Frederico Brito (USP)**

*Abstract:*

The work performed by a classical electromagnetic field on a quantum dipole is well known in quantum optics, where the absorbed power linearly depends on the time derivative of the average dipole moment. However, the problem concerning the work performed by a single-photon state on a quantum dipole still lacks an answer. As a matter of fact, the average quantum dipole moment exactly vanishes in such a scenario. In this talk, we address this problem. For that, quantum work is defined as the unitary contribution to the energy variation of the quantum dipole. It is shown that this definition furnishes a correspondence with the energy spent by the photon pulse to dynamically Stark shift the dipole. On the other hand, the non-unitary contribution to the dipole energy is defined here as a generalized quantum heat. It is shown that this generalized quantum heat is the energy corresponding to out-of-equilibrium photon absorption and emission. By providing physical means for being accessed, such connections for quantum work and generalized heat represent a step forward for such definitions. However, despite that advance, a quantitative relation between the generalized quantum heat and entropy production is still missing.

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

# QM Talks@CBPF: Pedro C. da Silva — 11.10, 16h00

**Posted:**October 5, 2017

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Quantum Information Group @ CBPF

Next in our series QM Talks@CBPF is a talk by Pedro C. da Silva, PhD student here at CBPF. In this talk Pedro will show some interesting results he got during his stay in Maryland, collaborating with the group of Prof. Stephen P. Jordan. Be sure to be there! Details follow.

Title: Quantum Algorithm for Simulating the Wave Equation

Speaker: Pedro C. da Silva (CBPF)

Coordinates: room 601C, CBPF. 11.10, 16h00

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 in state preparation relative to general purpose linear differential equation algorithms. We also consider using Hamiltonian simulation for Klein-Gordon equations and Maxwell’s equations.

# Talk @UFRJ, Daniel Tasca (UFF), Monday 09/10, 15H30

**Posted:**October 4, 2017

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

See the *details* of the talk below:

MONDAY, **October 9th**, at **15H30**

in room **343** (3rd floor of block A of the Technology Center building)

**“Mutual Unbiasedness in Coarse-grained Continuous Variables”**

**Daniel Tasca (UFF)**

*Abstract:*

The notion of mutual unbiasedness for coarse-grained measurements of quantum continuous variable systems is considered. It is shown that while the procedure of “standard” coarse graining breaks the mutual unbiasedness between conjugate variables, this desired feature can be theoretically established and experimentally observed in periodic coarse graining. We illustrate our results in an optics experiment implementing Fraunhofer diffraction through a periodic diffraction grating, finding excellent agreement with the derived theory. Our results are an important step in developing a formal connection between discrete and continuous variable quantum mechanics.

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You can incorporate our calendar to your *Google Calendar* and have information about all the confirmed seminars using the following link:

https://calendar.google.com/calendar/embed?src=3pne4irijnl5g41ulhvdc1h1g8%40group.calendar.google.com&ctz=America/Sao_Paulo

# Talk @UFF, Itay Hen (U. Southern California), Friday Oct. 6th, 11.00

**Posted:**October 3, 2017

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This Friday, Oct. 6th, at 11.00 Itay Hen (U. Southern California) will be giving the infoptics group talk, with title: “Limitations of and Hopes for Physical Quantum Annealers”. As usual, it’ll happen in room A5-01 of the Physics Building at UFF. All are welcome! For more information, please check below. Read the rest of this entry »

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