Le contenu de cette page n’est pas disponible en français. Veuillez nous en excuser.

Quantum Foundations

This series consists of talks in the area of Foundations of Quantum Theory. Seminar and group meetings will alternate.

Seminar Series Events/Videos

jan 17 2017 - 3:30pm
Room #: 294
Speaker(s):
Scientific Areas:

 

Mardi déc 06, 2016
Speaker(s): 

Analyzing characteristics of an unknown quantum system in a device-independent manner, i.e., using only the measurement statistics, is a fundamental task in quantum physics and quantum information theory. For example, device-independence is a very important feature in the study of quantum cryptography where the quantum devices may not be trusted.

Collection/Series: 
Scientific Areas: 

 

Jeudi déc 01, 2016
Speaker(s): 

A geometric approach to investigation of quantum entanglement is advocated.
We discuss first the geometry of the (N^2-1)--dimensional convex body
of  mixed quantum states acting  on an N--dimensional Hilbert space
and study projections of this set into 2- and 3-dimensional spaces.
For composed dimensions, N=K^2, one consideres the subset
of separable states and shows that it has a positive measure.
Analyzing its properties contributes to our understanding of
quantum entanglement and its time evolution.

Collection/Series: 
Scientific Areas: 

 

Mardi nov 29, 2016
Speaker(s): 

To describe observed phenomena in the lab and to apply superposition principle to gravity, quantum theory needs to be generalized to incorporate indefinite causal structure. Practically, indefinite causal structure offers advantage in communication and computation. Fundamentally, superposing causal structure is one approach to quantize gravity (spacetime metric is equivalent to causal structure plus conformal factor, so quantizing causal structure effectively quantizes gravity).

Collection/Series: 
Scientific Areas: 

 

Mardi nov 22, 2016
Speaker(s): 

The on-demand generation of bright entangled photon pairs is highly needed in quantum optics and emerging quantum information applications. However, a quantum light source combining both high fidelity and on-demand bright emission has proven elusive with current leading photon technologies. In this work we present a new bright nanoscale source of strongly entangled photon pairs generated with a position controlled nanowire quantum dot.

Collection/Series: 
Scientific Areas: 

 

Lundi nov 21, 2016
Speaker(s): 
Collection/Series: 
Scientific Areas: 

 

Mardi nov 15, 2016
Speaker(s): 

In this talk I will review the construction of space starting purely from quantum mechanics and without assuming that the notion of space is attached to a preconceived notion of classical reality. I will show that if one start with the simplest notion of a quantum system encoded into the Heisenberg group algebra one naturally obtain a notion of space that generalizes the usual notion of Euclidean space.

Collection/Series: 
Scientific Areas: 

 

Mardi nov 08, 2016
Speaker(s): 

Can we decompose the information of a composite system into terms arising from its parts and their interactions?

For a bipartite system (X,Y), the joint entropy can be written as an algebraic sum of three terms: the entropy of X alone, the entropy of Y alone, and the mutual information of X and Y, which comes with an opposite sign. This suggests a set-theoretical analogy: mutual information is a sort of "intersection", and joint entropy is a sort of "union".

Collection/Series: 
Scientific Areas: 

 

Jeudi oct 27, 2016
Speaker(s): 

In order to solve the problem of quantum gravity, we first need to pose the problem. In this talk I will argue that the problem of quantum gravity arises already in the domain of quantum mechanics and the relativity principle. Specifically, the relativity principle implies that the concept of inertial motion should extend also to those systems that are in quantum superpositions of inertial motions. By contrast, relativistic quantum field theory only considers the point of view of classical observers in states of definite relative motion (i.e.

Collection/Series: 

 

Mardi oct 25, 2016
Speaker(s): 

I will explain and prove the statement of the title. The proof relies on a recent result of Slofstra in combinatorial group theory and the hypergraph approach to contextuality.

Based on http://arxiv.org/abs/1607.05870.

Collection/Series: 
Scientific Areas: 

 

Mardi oct 18, 2016
Speaker(s): 

In quantum information, we frequently consider (for instance, whenever we talk about entanglement) a composite system consisting of two separated subsystems. A standard axiom of quantum mechanics states that a composite system can be modeled as the tensor product of the two subsystems. However, there is another less restrictive way to model a composite system, which is used in quantum field theory: we can require only that the algebras of observables for each subsystem commute within some larger subalgebra.

Collection/Series: 
Scientific Areas: 

Pages