On Wed 28 October, 2PM AQM room @ LITA 5th floor Hossein Rangani (Urmia University, Iran) will deliver a talk entitled

# Category Archives: Seminars

# Paolo Giorda’s talk

On Wednesday 21 October, 2PM AQM Room, Paolo Giorda (INRIM Torino) will be with us and deliver a talk entitled

#### Quantum effects in open systems dynamics and their roots in the Decoherent Histories Approach. An application to energy transfer processes in simple photosynthetic systems: the Quantum Recoil Avoiding effect and energy transfer efficiency.

# Jacopo Trapani and Giacomo Guarnieri talks

On Wednesday 7 October, 2PM AQM room @ LITA 5th floor (together with a coffee), Jacopo Trapani and Giacomo Guarnieri (PhD student @ UNIMI) will deliver their 2-nd year seminars

2 PM **Jacopo Trapani**

#### Noisy quantum phase communication channels.

2:30 PM **Giacomo Guarnieri**

#### Energy backflow and non-Markovian dynamics

# Matteo Rossi talk

Matteo Rossi will deliver his summer-school seminar on Wednesday 30 September, at 2 PM at Auletta di Ottica Quantistica (5th floor LITA building), entitled *“Quantum estimation from incomplete information”*.

# Antonio Mandarino talk

Antonio Mandarino, will deliver a talk on Wednesday, September 23th 2015, 2 PM at the Auletta di Ottica Quantistica (LITA 5th floor).

### Fidelity in tomographic reconstruction of continuous variable systems

Abstract: Fidelity is a widely adopted measure of closeness between quantum states either pure or mixed. Although it is not a proper distance in the Hilbert space, fidelity can be linked to distances inducing a metric over the manifold of density matrix. This relation is commonly adopted to justify the assumption that states with a high value of fidelity, viz. 0.9 or 0.99 is enough to certify that two states shares identical physical properties. We analyze a set of experimentally generated quantum states by means of tomographic analysis. Hence we will show that benchmarking with the usual fidelity thresholds does not accomplish that task, in addition we emphasise how only full quantum tomography does.

# Stefano Pirandola talk at AQM

We are glad to announce that Stefano Pirandola (University of York) will deliver a talk on Tuesday 14 July at the Aula di Ottica Quantistica (5th floor LITA building). An abstract of the talk follows.

#### Stefano Pirandola (University of York)

#### Relay-based protocols in correlated-noise Gaussian environments

We consider continuous-variable protocols exploiting a quantum relay, such as entanglement swapping, quantum teleportation, and QKD. Their theory is extended to a non-Markovian spatial model of decoherence characterized by correlated Gaussian noise. Even if bipartite entanglement is completely lost at the relay, we show that the various protocols can progressively be reactivated by the separable noise-correlations of the environment.

# Elsi-Mari Laine and Massimo Borrelli visiting AQM

Elsi-Mari Laine and Massimo Borrelli from the University of Turku (Finland) will visit us from Monday 13 to Friday 17 July.

They will deliver two talks on Wednesday 15 July.

Room: Aula di Ottica Quantistica (5th floor LITA building)

#### 17:00: Elsi-Mari Laine (University of Turku)

#### “Dynamics of incompatibility of quantum measurements in open systems”

The non-classical nature of quantum states, whether depicted with entanglement or quantum discord, is often considered as resource for quantum information protocols. However, the non-classicality of a quantum system cannot be encapsulated as a property of the state alone, as the set of available measurements used to extract information on the system may also be restricted. In this work we study how the non-classicality of quantum measurements, quantified via their incompatibility, is influenced by quantum noise and, further, how a non-Markovian environment may help us in maintaining the measurement resources.

#### 17:30: Massimo Borrelli (University of Turku)

#### “Quantum probing of complex systems”

Quantum probes are controllable quantum objects that can be used to investigate complex systems via tailored, engineered interactions. By monitoring the dynamics of the probe(s) one can directly access some of the complex system’s features, such as average quantities and correlations. In this talk we are going to give a brief introduction to quantum probes, with particular emphasis on the open-system approach. Furthermore, we are going to discuss a few examples of successful applications of quantum probing to many-body systems.

# Talk by Gianluca Oppo on May 12, 2015

We are glad to announce a talk by **Gianluca Oppo** (University of Strathclyde) which will take place on **May 12**, at **15:00**, in **Sala Polvani**.** **Here in the following the title and abstract:

## Opto-mecahnics of cold atoms and Bose-Einstein Condensates

#### Gianluca Oppo, University of Strathclyde

*We consider theoretically and experimentally the behaviour of cold or ultra-cold atoms interacting with a laser beam in an optical cavity or in a single-feedback mirror set-up. The optical nonlinearity is augmented by the presence of the dipole force where atoms tend to move towards minima or maxima of the light intensity depending on the the difference between their resonant frequency and the frequency **of the laser light (opto-mechanics). We observe novel Turing patterns entirely due to opto-mechanic effects in a cloud of cold Rubidium atoms under the action of an input laser beam and a feedback mirror. The role of the (cold) temperature is essential in these experimental measures. We then generalise these spatial features to the case of cold atoms in a cavity where dissipative solitons appear in the atomic density as well as in the light intensity distribution.*

*When considering ultra-cold atomic gases (Bose-Einstein condensates) new quantum features appear in the form of a threshold for pattern formation in the atomic density driven by the Heisenberg*

*indetermination principle. We also show that conservative chaos occurs in spite of the presence of the external driving and energy dissipation from the cavity mirrors.*

# Quantum EXPO workshop on Feb 24

The next Quantum Expo workshop, on the topic *Quantum Information and Control*, will be held on **Wednesday, February 24, 2015** at the Physics Department of the University of Milan (**Aula Polvani**) at **11:00**. Here is the program of the workshop:

##### 11:00 Stefano Mancini (Università di Camerino)

Entanglement assisted feedback control

##### 11:50 Young scientist seminar

##### Michele Avalle

Transport process and typicality of noisy quantum systems with discrete time

##### 14:30 Marco G. Genoni (University College London)

Cooling and squeezing generation for a levitated nanosphere via time-continuous measurements

Download the poster with program and abstracts!

# Quantum Expo workshop on Feb 18

The next Quantum Expo workshop, on the topic *Quantum estimation with classical and nonclassical states,* will be held on **February 18, 2015** at the Physics Department of the University of Milan (**Aula Polvani**) at **11:00**. The workshop will feature talks by Gerardo Adesso (University of Nottingham) and Daniel Braun (Universität Tübingen).

Download the poster with program and abstracts!