Events

A conference to celebrate the work of Chris Godsil

It is surprising that the characteristic polynomial of the adjacency matrix of a graph provides a useful window onto combinatorial properties of the graph itself, but this approach to graph theory has been a source of interesting and useful results for over 80 years.

Ramy El Ganainy, Michigan Technological University

Robin Kothari

I will talk about a classic lemma due to Jordan (1875) that is
frequently used in quantum computing.  Jordan's lemma says that given
any two orthogonal projectors, there is a way to partition the
underlying vector space into 1- and 2-dimensional subspaces that are
invariant under the action of both projectors.  This simple lemma has
applications in several areas of quantum computing.  In this talk will
discuss the lemma, its proof, and explain some selected applications in

Dominique Unruh, University of Tartu

Position verification allows us to verify the position of a device in space (e.g., for enabling access to location based services). Unfortunately, position verification is known to be insecure in principle using only classical cryptography. We show how position verification can be achieved using quantum communication.

Karol Zyczkowski, Jagellonian University

A pure quantum state of N subsystems with d levels each is called
k-uniform, if all its reductions to k qudits are maximally mixed.
These states form a natural generalization of N-qudits GHZ states
which belong to the class 1-uniform states.

Sergey Bravyi, IBM Research

Stoquastic Hamiltonians are characterized by the property that their off-diagonal matrix elements in the standard product basis are real and non-positive. Many interesting quantum models fall into this class including the Transverse field Ising Model (TIM), the Heisenberg model on bipartite graphs, and the bosonic Hubbard model.

Quantum algorithms exponentially faster than their classical equivalents exist for code breaking, quantum chemistry, knot theory, group theory, and are speculated to exist for diverse applications including machine learning and artificial intelligence. I review these applications and the current state of knowledge on how to build a practical quantum computer.

Alexander Szameit, Friedrich-Schiller-Universität Jena

I report about our recent achievements on integrated photonic quantum circuits. For the fabrication we use direct laser-inscription, which allows complex three-dimensional waveguide architectures on chip for using multiple degrees of freedom, in particular diffraction control and birefringence.

Genda Gu, Brookhaven National Laboratory

Gregor Weihs, Institut für Experimentalphysik, Universität Innsbruck

For fundamental tests of quantum physics as well as for quantum communications non-classical states of light are an important tool. In our research we focus on developing semiconductor-based and integrated sources of single photons and entangled photon pairs.