Upcoming seminars

Coherence amplification by an autonomous quantum thermal machine

Seminar date and time: 
2016-09-21 14:30
Author: 
Juan MR Parrondo
Affiliation: 
Universidad Complutense de Madrid

We present a model for an autonomous quantum thermal machine comprised of two qubits that is capable of amplifying the coherence in a non-degenerate system by using only thermal resources. This novel method of coherent control allows for the interconversion between energy, both work and heat, and coherence.

 

Location: 
GIQ Seminar room

Course on "Some Elementary Remarks concerning Quantum versus Classical Statistical Physics"

Seminar date and time: 
2016-09-19 10:00 to 2016-09-21 11:30
Author: 
Jean Zinn-Justin

Dr. Zinn-Justin attended École Polytechnique for his undergraduate degree, graduating in 1964. He continued his research under Marcel Froissart at the University of Orsay, earning a Ph.D. in 1968. While Zinn-Justin has had a permanent position with the CEA-Saclay theory group, he has also held visiting positions as SUNY Stony-Brook, CERN, Princeton, Harvard, and MIT. 

Nonequilibrium thermodynamics in the strong coupling and non-Markovian regime based on a reaction coordinate mapping

Seminar date and time: 
2016-09-15 14:30
Author: 
Philipp Strasberg
Affiliation: 
Institut für Theoretische Physik, Technische Universität Berlin

We propose a method to study the thermodynamic behaviour of small systems beyond the weak coupling and Markovian approximation, which is different in spirit from conventional approaches. The idea is to redefine the system and environment such that the effective, redefined system is again coupled weakly to Markovian residual baths and thus, allows to derive a consistent thermodynamic framework for this new system-environment partition.

Location: 
GIQ Seminar room

Challenges in experimental certification in high dimensional entanglement

Seminar date and time: 
2016-09-13 14:30
Author: 
Marcus Huber
Affiliation: 
Institute for Quantum Optics and Quantum Information, Austrian Academy of Sciences (Vienna)

In this seminar I would like to present and discuss recent progress on the certification of high-dimensional entanglement. High dimensional entanglement promises to improve quantum communication protocols in numerous ways, but poses a number of challenges in its use. I will shortly present a couple of new techniques to quantify entanglement with only  limited access to measurements, and present various open problems in this context. The talk is based on past and upcoming experiments in this field [1,2], as well as a recent proposal [3]:

Location: 
GIQ Seminar room

Improved sensing with a single qubit

Seminar date and time: 
2016-07-13 14:30
Author: 
Pavel Sekatski
Affiliation: 
Institut für Theoretische Physik, Universitat Innbsbruck.

We consider frequency estimation with a arbitrary prior knowledge of the parameter. We demonstrate that a single sensing two-level system can act as a virtual multi-level system that offers increased precision in such a Bayesian frequency estimation scenario, and that allows one to estimate (arbitrary) large parameter values by avoiding phase wraps. This is achieved by making use of additional degrees of freedom or auxiliary systems not influenced by the sensing interaction.

Converse bounds for private communication over quantum channels

Seminar date and time: 
2016-07-07 15:30
Author: 
Mark Wilde
Affiliation: 
Hearne Institute for Theoretical Physics, Department of Physics and Astronomy, Center for Computation and Technology, Louisiana State University, Baton Rouge, Louisiana 70803, USA

We establish several converse bounds on the private transmission capabilities of a quantum channel. The main conceptual development builds firmly on the notion of a private state [Horodecki et al., PRL 94, 160502 (2005)], which is a powerful, uniquely quantum method for simplifying the tripartite picture of privacy involving local operations and public classical communication to a bipartite picture of quantum privacy involving local operations and classical communication.

Higher order interference versus quantum theory

Seminar date and time: 
2016-07-07 14:30 to 15:30
Author: 
Howard Barnum
Affiliation: 
University of New Mexico and Leibniz University Hannover

We (Ududec, Barnum, and Emerson) adapt Rafael Sorkin's hierarchy of
orders of interference in physical theories to the framework of
"general probabilistic theories", defining a notion of k-path
interference experiment and of k-th order coherence in such theories
and showing that k-th order interference in such an experiment is
equivalent to k-th order coherence between faces of the state spaces
associated with paths in the experiment. We also show that
Jordan-algebraic theories have at most second-order interference (the

Operator space and its application to Bell and steering inequalities

Seminar date and time: 
2016-07-06 14:30 to 15:30
Author: 
Zhi Yin
Affiliation: 
Wuhan University

The idea of the operator space is to quantize Banach  space, where the completely bounded map plays an important role. Due to Junge and his coauthors groundbreaking work, operator space theory was used to derive Bell inequalities with unbounded violation. In this seminar, we will recall their approach and introduce our work in steering inequalities.

Pages

Campus d'excel·lència internacional U A B